ORCID Profile
0000-0002-6485-1643
Current Organisations
University of South Australia
,
University of Melbourne
,
University of Adelaide
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Publisher: American Psychological Association (APA)
Date: 04-2021
DOI: 10.1037/HEA0001062
Publisher: Informa UK Limited
Date: 06-2019
DOI: 10.1111/AJPY.12227
Publisher: Wiley
Date: 21-11-2017
DOI: 10.1111/JSR.12473
Abstract: This laboratory study investigated the impact of restricted sleep during a simulated school week on circadian phase, sleep stages and daytime functioning. Changes were examined across and within days and during a simulated weekend recovery. Participants were 12 healthy secondary school students (six male) aged 15-17 years [mean = 16.1 years, standard deviation (SD) = 0.9]. After 2 nights with 10 h (21:30-07:30 hours), time in bed was restricted to 5 h for 5 nights (02:30-07:30 hours), then returned to 10 h time in bed for 2 nights (21:30-07:30 hours). Saliva was collected in dim light on the first and last sleep restriction nights to measure melatonin onset phase. Sleep was recorded polysomnographically, and the Psychomotor Vigilance Task (PVT) and Karolinska Sleepiness Scale were undertaken 3-hourly while awake. Average phase delay measured by melatonin was 3 h (SD = 50 min). Compared to baseline, sleep during the restriction period contained a smaller percentage of Stages 1 and 2 and rapid eye movement (REM) and a greater percentage of Stage 4. PVT lapses increased significantly during sleep restriction and did not return to baseline levels during recovery. Subjective sleepiness showed a similar pattern during restriction, but returned to baseline levels during recovery. Results suggest that sustained attention in adolescents is affected negatively by sleep restriction, particularly in the early morning, and that a weekend of recovery sleep is insufficient to restore performance. The discrepancy between sleepiness ratings and performance may indicate a lack of perception of this residual impairment.
Publisher: National Institute of Industrial Health
Date: 16-11-2022
Publisher: MDPI AG
Date: 15-11-2021
DOI: 10.3390/NU13114087
Abstract: Unusual meal timing has been associated with a higher prevalence of chronic disease. Those at greater risk include shift workers and evening chronotypes. This study aimed to validate the content of a Chrononutrition Questionnaire for shift and non-shift workers to identify temporal patterns of eating in relation to chronotype. Content validity was determined using a Delphi study of three rounds. Experts rated the relevance of, and provided feedback on, 46 items across seven outcomes: meal regularity, times of first eating occasion, last eating occasion, largest meal, main meals/snacks, wake, and sleep, which were edited in response. Items with greater than 70% consensus of relevance were accepted. Rounds one, two, and three had 28, 26, and 24 experts, respectively. Across three rounds, no outcomes were irrelevant, but seven were merged into three for ease of usage, and two sections were added for experts to rate and comment on. In the final round, all but one of 29 items achieved greater than 70% consensus of relevance with no further changes. The Chrononutrition Questionnaire was deemed relevant to experts in circadian biology and chrononutrition, and could represent a convenient tool to assess temporal patterns of eating in relation to chronotype in future studies.
Publisher: BMJ
Date: 04-2004
Abstract: To determine whether the amount of joint cartilage in healthy postmenopausal women is stable or changes over time, and whether oestrogen replacement therapy (ERT) influences this. A cohort study in healthy postmenopausal women without knee pain, initially selected on the basis of having either used ERT long term (more than five years) or never having used ERT. 81 women (42 taking ERT and 39 non-users) had baseline knee radiographs and magnetic resonance imaging (MRI) on the dominant knee 57 of these (70%) were followed with repeat MRI approximately 2.5 years later. Knee cartilage volume was measured at baseline and at follow up. Risk factors assessed at baseline, including ERT use, were tested for their association with change in knee cartilage volume over time. 29 subjects who were initially taking ERT and 28 non-users at baseline completed the study. Total tibial articular cartilage decreased, on average, by (mean (SD)) 2.4 (3.2)% per year (95% confidence interval for mean, 1.5% to 3.2%). Average annual reduction in medial and lateral tibial cartilage was 2.4 (3.6)% (1.4% to 3.3%) and 2.3 (4.2)% (1.2% to 3.4%), respectively. No association between ERT and the rate of reduction in cartilage volume was shown. Mean tibial cartilage volume loss in healthy postmenopausal women is between 1.5% and 3.2% a year. Whether this rate of change is similar throughout adult life or in men will require further investigation.
Publisher: Informa UK Limited
Date: 06-2010
DOI: 10.3109/07420528.2010.489439
Abstract: The objective of the study was to describe the work and sleep patterns of doctors working in Australian hospitals. Specifically, the aim was to examine the influence of work-related factors, such as hospital type, seniority, and specialty on work hours and their impact on sleep. A total of 635 work periods from 78 doctors were analyzed together with associated sleep history. Work and sleep diary information was validated against an objective measure of sleep/wake activity to provide the first comprehensive database linking work and sleep for in idual hospital doctors in Australia. Doctors in large and small facilities had fewer days without work than those doctors working in medium-sized facilities. There were no significant differences in the total hours worked across these three categories of seniority however, mid-career and senior doctors worked more overnight and weekend on-call periods than junior doctors. With respect to sleep, although higher work hours were related to less sleep, short sleeps (< 5 h in the 24 h prior to starting work) were observed at all levels of prior work history (including no work). In this population of Australian hospital doctors, total hours worked do impact sleep, but the pattern of work, together with other nonwork factors are also important mediators.
Publisher: National Institute of Industrial Health
Date: 2019
Publisher: American Academy of Sleep Medicine (AASM)
Date: 15-08-2018
DOI: 10.5664/JCSM.7280
Publisher: Research Square Platform LLC
Date: 23-05-2020
Abstract: Background: There is a discordance in classification of obesity when defined by body mass index (BMI) or waist circumference (WC). We aimed to examine whether categories of BMI- and WC-defined obesity are differentially associated with the risk of total knee arthroplasty for osteoarthritis. Methods: 38,924 participants from the Melbourne Collaborative Cohort Study with BMI and WC measured at baseline (1990-1994) were included. Obesity status was defined as: not obese (non-obese BMI and non-obese WC) WC-defined obesity only (non-obese BMI and obese WC) BMI-defined obesity only (non-obese WC and obese BMI) and BMI- and WC-defined obesity. The incidence of total knee arthroplasty for osteoarthritis between January 2001 and December 2013 was determined by linking participant records to the National Joint Replacement Registry. Results: Over 11.5±3.1 years follow-up, 1,875 participants underwent total knee arthroplasty for osteoarthritis. Participants with WC-defined obesity only (HR=1.79, 95%CI 1.51-2.53), BMI-defined obesity only (HR=2.39, 95%CI 2.02-2.84), and BMI- and WC-defined obesity (HR=3.14, 95%CI 2.82-3.49) had an increased risk of total knee arthroplasty compared with those who were not obese. Conclusions: In iduals with either BMI- or WC-defined obesity should be targeted for prevention of knee osteoarthritis as both are significant predictors for severe osteoarthritis requiring a total knee arthroplasty.
Publisher: FapUNIFESP (SciELO)
Date: 10-2011
DOI: 10.1590/S0034-89102011005000059
Abstract: OBJECTIVE: To describe sleep, stress and compensatory behaviors in nurses and midwives. METHODS: The study included 41 midwives and 21 nurses working in Australian hospitals between 2005 and 2009. Participation was voluntary. All participants recorded on a daily basis their work and sleep hours, levels of stress and exhaustion, caffeine intake and use of sleep aids for a month (1,736 days, 1,002 work shifts). RESULTS: Participants reported moderate to high levels of stress and exhaustion on 20-40% of work days experienced sleep disruption on more than 50% of work days struggled to remain awake on 27% of work days and suffered extreme drowsiness or experienced a near accident while travelling home on 9% of workdays. Age, perceived sleep duration and work hours were significant predictors of caffeine intake. About 60% of participants reported using sleep aids (about 20% reported taking prescription medications and 44% of nurses and 9% of midwives reported alcohol use as a sleep aid at least once during the study). Stress and workdays were significant predictors of sedative use. Overall, 22% reported being indifferent or mildly dissatisfied with their job. CONCLUSIONS: Sleep problems, high levels of stress and exhaustion and low job satisfaction are prevalent among nurses and midwives. The use of alcohol and sleeping pills as sleep aids, and the use of caffeine to help maintain alertness is also common. Nurses and midwives may use caffeine to compensate for reduced sleep, especially on workdays, and sleeping pills to cope with their daily work-related stress.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.NEDT.2019.104298
Abstract: There is a disconnect between what maternity care providers consider should be done and what they actually do with respect to talking with their pregnant clients about reducing their risk of stillbirth. This suggests that they would benefit from receiving up-to-date knowledge about stillbirth, alongside education that provides them with strategies for talking about stillbirth with pregnant women. To gain an understanding of maternity care provider (obstetricians and midwives) knowledge of stillbirth and determine whether delivering a half day workshop improves knowledge and results in intention to change practice. A pre-post intervention study. Maternity care providers (Obstetricians, Midwives) working in the northern areas of Tasmania, Australia were asked, via questionnaire, about their knowledge of stillbirth both before and after attending a half-day workshop. Maternity care providers (n = 51) attended the workshop and 30 (59%) completed both the pre-workshop and post-workshop surveys. A four hour interactive workshop grounded in understanding the stillbirth experience. Participants were given up-to-date information about stillbirth risks and current prevention research as well as provided with an actionable step wise approach to talking about stillbirth prevention in pregnancy. Stillbirth knowledge scores (total of 8-points) significantly increased following the workshop (pre: mean = 2.9 ± 1.5 post: mean = 4.7 ± 1.4 points, t Attending a stillbirth awareness for prevention education workshop resulted in significant knowledge improvement and self-reported intention to change practice in a group of Australian maternity care providers. While these results are promising, further study is needed to determine the presence and extent of actual practice change following such education.
Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.NEDT.2008.08.010
Abstract: While flexible delivery techniques, including online technologies, are becoming widely used to cater for the differing needs of students, they are not always met with enthusiasm, and can cause anxiety in students who are unfamiliar with the online environment. Online delivery of a first year nursing course (for distance learning and face-to-face provision) was introduced to facilitate reliable student-staff and student-student communication and streamline assessment procedures during a period in which class sizes increased (from 500 in 2003 to more than 650 in 2004 and 2005). Results of an evaluation exercise are presented, which aimed to: (1) trial online methods for course delivery and assignment submission (2) canvass both student and staff responses to these innovations (3) identify areas requiring change/improvement and (4) formulate a strategy for improvement and continuing use of the technologies. Results suggested a positive response to the innovations by both staff and students. However, several implementation issues were identified, as were suggestions to overcome these initial hurdles. Iterative re-evaluation and continual development will examine the total benefit of these improvements. Taken together, this process has highlighted the importance of open communication, reducing anxiety and resistance to innovation, formal and informal evaluation processes and continued systems development.
Publisher: National Institute of Industrial Health
Date: 2016
Publisher: Elsevier BV
Date: 09-2004
DOI: 10.1016/S1440-2440(04)80030-6
Abstract: Osteoarthritis (OA) is the most common form of arthritis and is a major cause of disability in people aged over 65. Despite the major socioeconomic burden imposed by OA, the aetiology of this condition remains unclear. Although controversial, several metabolic factors have been implicated in the disease pathogenesis. Nevertheless, no unequivocal systemic risk factors for the onset or progression of OA have been identified. Recently, there has been a growing interest in the biomechanical factors associated with the pathogenesis of OA. This review aims to discuss several of the more pertinent biomechanical and neuromuscular factors, such as the knee adduction moment and muscle strength, that are becoming increasingly accepted as factors that contribute toward the pathogenesis of knee OA.
Publisher: American Psychological Association (APA)
Date: 11-2010
DOI: 10.1037/A0020714
Publisher: BMJ
Date: 2002
DOI: 10.1136/ARD.61.1.86
Publisher: National Institute of Industrial Health
Date: 2005
Abstract: The aim of the study was to examine the adaptation of participants to a common night work schedule using urinary 6-sulphatoxymelatonin (aMT6s) concentration as the circadian phase marker. Fifteen adults (7 male, 8 female, age = 21.9 yr) spent nine consecutive nights in the laboratory, including: (i) adaptation sleep, (ii) baseline sleep, and (iii) seven simulated night shifts (23:00-07:00 h) followed by daytime sleep. During the baseline and daytime sleeps, participants collected urine s les which were subsequently assayed for aMT6s. The concentration of aMT6s in urine for the first three day sleeps was significantly lower than for the baseline sleep, but there was no difference in aMT6s concentrations between any of the last three day sleeps and the baseline sleep. The data indicate that people may adapt to a pattern of work that includes seven consecutive night shifts if they adhere to a fixed sleep schedule, if their exposure to morning sunlight is minimised, and if they are provided with an ideal sleep environment.
Publisher: MDPI AG
Date: 15-02-2023
DOI: 10.3390/NU15040959
Abstract: The negative impact of an unhealthy diet on the shiftworker population has been well-documented. However, little evidence exists on the underlying reasons for unhealthy eating behaviours and the existing barriers to healthy eating withinshiftwork environments. This qualitative study investigated the dietary behaviours reported by shiftworkers through Facebook comments. Comments were collected if they were on public shiftworker-relevant posts pertaining to dietary news or dietary information on Facebook and were posted by self-identified shiftworkers, relatives of shiftworkers, or partners of shiftworkers. A thematic analysis of the 144 comments collected generated four categories that can be used to understand the motivations for eating behaviour on-shift: what shiftworkers eat, where food is sourced from, when food is eaten, and why certain foods are chosen. Results reveal motivations, attitudes, and both internal and external barriers to healthy eating behaviours, as well as similarities and differences across shiftwork industries. Recommendations for future research include further explorations on the link between scheduled eating (e.g., time-restricted eating) and shiftwork, the impact of a rotating shift arrangements on dietary health behaviours, and the impact of interpersonal relationships on shiftworker dietary choices. Understanding these motivations will inform strategies to promote healthy eating and help understand barriers for shiftworkers.
Publisher: National Institute of Industrial Health
Date: 2019
Publisher: Scandinavian Journal of Work, Environment and Health
Date: 26-02-2019
DOI: 10.5271/SJWEH.3803
Abstract: Objectives Unhealthy dietary profiles contribute to the elevated risk of chronic diseases for shift workers. There has been limited investigation into factors associated both with shift work and diet, such as sleep and mood, that may further influence food intake among shift workers. The aim of this study was to explore the relationship between shift work, sleep, mood, and diet. Methods Shift working nurses [N=52 46 female age: mean 39.8 (SD 12.4) years] participated in a 14-day, repeated measures, within- and between-subjects design study. Analyses included data from 40 nurses over 181 shifts. Food diaries were completed for a minimum of three days per shift type (morning, afternoon, night). Foodworks nutrition software was used to determine energy intake in kilojoules and macronutrient intake (as a percentage of total energy intake). Mood (happiness, anxiety, depressive mood, stress, and tiredness) was measured using visual analog scales. Sleep was estimated using actigraphy. Demographic and work-related variables (covariates) were measured using a modified version of the Standard Shiftwork Index. A path analysis was conducted using generalized structural equation modelling with a random effect of participant ID. Predictors were selected using purposive selection of covariates (an alternative to stepwise modelling) and final models included important predictors only. Results Compared to night and morning shifts, results showed that working an afternoon shift was associated with a lower energy intake (β= -1659.4, P<0.01) and lower levels of stress (β= -5.6, P<0.01). Higher levels of stress were associated with a higher energy intake (β=35.3, P<0.01) and a higher percentage of fat (ß=0.1, P=0.05) and saturated fat (β=0.1, P<0.01). Compared to the other shift types, morning shift was associated with lower carbohydrates (β= -4.3, P<0.01) and night shift was associated with lower protein (β= -2.7, P=0.03). Lower sleep efficiency was associated with a higher carbohydrate intake (β= -0.4, P<0.01) and a lower protein intake (β=0.25, P<0.01) Conclusions Results suggest that compared to nights and mornings, afternoon shifts were associated with reduced energy consumption. Negative mood (stress, depression, and anxiety) mediated the association between shift type and energy intake. Negative mood was also associated with higher fat intake. Dietary interventions for shift workers should consider the role of mood as well as shift type.
Publisher: BMJ
Date: 09-2004
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.AAP.2011.09.019
Abstract: Biomathematical models are used in industry to estimate how much sleep people are likely to get on different work patterns, and how efficient and safe people are likely to be at work. Since there is evidence to suggest that in iduals respond differently to sleep loss, there has been a recent focus on trying to account for in idual differences. One possible approach could use past behaviour to predict future responses to similar working conditions. This study investigated the predictive value of sleep timing and duration data for a particular in idual on a break between shifts relative to data from their colleagues. Sleep diaries and wrist actigraphy were collected from 306 international long-haul pilots for at least 2-weeks. Fifty layovers, equivalent in origin and destination, length and timing, were completed twice by in idual pilots. Matched layovers done by other pilots (n=2311) were also identified. Layover periods were analysed for minute-by-minute correspondence of sleep or wake (yes/no), and total sleep time (TST). Using an in idual's own data improved concordance by approximately 5% relative to using a large s le of different pilots, and by 10% relative to using a random s le of 50 different pilots. Using an in idual's own TST to predict their TST on an equivalent layover yielded an r value of 0.83, compared to r=0.78 when data from a colleague was used, and r=0.73 using different pilots in a random s le of equivalent size. The mean difference in TST using pilots' own data was <20 min, compared to <40 min using data from colleagues. However, the confidence limits on these differences were large (up to 8h). Results suggest that for international pilots on specific layover patterns, knowing the past behaviour of an in idual may only represent a modest improvement over knowing the length and timing of a colleague's sleep, when it comes to predicting their sleep behaviour.
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.APERGO.2017.12.006
Abstract: Situation awareness (SA) is an important component of an in idual's ability to function in a complex environment. As such, it is essential to have effective measures of an in idual's SA. The most widely used subjective measure of SA is the Situation Awareness Rating Technique [SART]. However, SART has been criticised for not predicting performance or objective SA, and being highly correlated with workload. This paper describes the development and testing of a new subjective measure of SA, the Low-Event Task Subjective Situation Awareness (LETSSA) measure. To evaluate LETSSA a train simulator study was conducted with 23 novice and 26 expert freight train drivers. LETSSA was able to detect differences in manipulated SA and was comparable to an established objective SA measure (SAGAT). LETSSA was significantly associated with performance but not significantly associated with workload. While further validation is required, LETSSA shows promise as an effective subjective measure of SA.
Publisher: BMJ
Date: 07-2005
Publisher: Wiley
Date: 19-05-2009
DOI: 10.1111/J.1365-2869.2008.00716.X
Abstract: The impact of sleep restriction on sustained attention in children has not been well quantified. To address this shortcoming, this study tested the sensitivity of a 5-min personal digital assistant-psychomotor vigilance task (PDA-PVT) to sleep restriction in 14 female children [mean (SD) age = 10.6 +/- 0.3 years]. The children underwent PDA-PVT trials at regular intervals both before and after a sleep restriction (5 h time-in-bed) and a control (10 h time-in-bed) condition. Sleep restriction was associated with longer mean response times and increased number of lapses. These results are consistent with findings in the adult literature suggesting an association between inadequate sleep and impaired functioning. In conclusion, the 5-min PDA-PVT is sensitive to sleep restriction in pre-adolescent female children supporting the utility of the PDA-PVT for examining the impact of sleep deprivation on daytime functioning in children.
Publisher: Elsevier BV
Date: 07-2006
Publisher: Informa UK Limited
Date: 21-06-2017
DOI: 10.1080/07420528.2017.1335318
Abstract: Eating during the night may increase the risk for obesity and type 2 diabetes in shift workers. This study examined the impact of either eating or not eating a meal at night on glucose metabolism. Participants underwent four nights of simulated night work (SW1-4, 16:00-10:00 h, <50 lux) with a daytime sleep opportunity each day (10:00-16:00 h, <3 lux). Healthy males were assigned to an eating at night (NE n = 4, meals 07:00, 19:00 and 01:30 h) or not eating at night (NEN n = 7, meals 07:00 h, 09:30, 16:10 and 19:00 h) condition. Meal tolerance tests were conducted post breakfast on pre-night shift (PRE), SW4 and following return to day shift (RTDS), and glucose and insulin area under the curve (AUC) were calculated. Mixed-effects ANOVAs were used with fixed effects of condition and day, and their interactions, and a random effect of subject identifier on the intercept. Fasting glucose and insulin were not altered by day or condition. There were significant effects of day and condition × day (both p < 0.001) for glucose AUC, with increased glucose AUC observed solely in the NE condition from PRE to SW4 (p = 0.05) and PRE to RTDS (p < 0.001). There was also a significant effect of day (p = 0.007) but not condition × day (p = 0.825) for insulin AUC, with increased insulin from PRE to RTDS in both eating at night (p = 0.040) and not eating at night (p = 0.006) conditions. Results in this small, healthy s le suggest that not eating at night may limit the metabolic consequences of simulated night work. Further study is needed to explore whether matching food intake to the biological clock could reduce the burden of type 2 diabetes in shift workers.
Publisher: Informa UK Limited
Date: 14-04-2016
DOI: 10.3109/07420528.2016.1167724
Abstract: Sleep inertia is a safety concern for shift workers returning to work soon after waking up. Split duty schedules offer an alternative to longer shift periods, but introduce additional wake-ups and may therefore increase risk of sleep inertia. This study investigated sleep inertia across a split duty schedule. Sixteen participants (age range 21-36 years 10 females) participated in a 9-day laboratory study with two baseline nights (10 h time in bed, [TIB]), four 24-h periods of a 6-h on/6-h off split duty schedule (5-h TIB in off period 10-h TIB per 24 h) and two recovery nights. Two complementary rosters were evaluated, with the timing of sleep and wake alternating between the two rosters (2 am/2 pm wake-up roster versus 8 am/8 pm wake-up roster). At 2, 17, 32 and 47 min after scheduled awakening, participants completed an 8-min inertia test bout, which included a 3-min psychomotor vigilance test (PVT-B), a 3-min Digit-Symbol Substitution Task (DSST), the Karolinska Sleepiness Scale (KSS), and the Samn-Perelli Fatigue Scale (SP-Fatigue). Further testing occurred every 2 h during scheduled wakefulness. Performance was consistently degraded and subjective sleepiness/fatigue was consistently increased during the inertia testing period as compared to other testing times. Morning wake-ups (2 am and 8 am) were associated with higher levels of sleep inertia than later wake-ups (2 pm and 8 pm). These results suggest that split duty workers should recognise the potential for sleep inertia after waking, especially during the morning hours.
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.ANAI.2022.05.008
Abstract: It is not clear which allergic disease is most strongly related to which sleep problem and whether sleep problems may mediate the association between allergic disease and psychological distress. There is also a need for more community-based studies using nonreferred s les. To evaluate the association between in idual allergic diseases and sleep problems and test whether the association between allergic disease and psychological distress is mediated through sleep problems. Parents of 1449 Australian children aged 6 to 10 years recruited from the general community, completed measures of sleep problems (Pediatric Sleep Survey Instrument), psychological distress (Strengths and Difficulties Questionnaire), and frequency of allergic diseases. Sleep and psychological distress scores were in the reference range. After controlling for coexisting allergic diseases, allergic rhinitis was associated with sleep routine problems, morning tiredness, night arousals, sleep disordered breathing and restless sleep asthma with sleep routine problems, sleep disordered breathing and restless sleep and eczema with restless sleep. Path analyses revealed that sleep problems mediated the association between asthma and allergic rhinitis but not eczema with psychological distress. In this nonreferred community s le, the frequency of sleep problems and psychological distress was lower than that typically reported in children referred to specialized centers. However, allergic rhinitis was associated with a broad range of sleep problems and to a lesser extent in children with asthma and least in children with eczema. Path analysis revealed that the association between allergic disease and psychological distress was mediated through sleep problems, highlighting the importance of assessing sleep health in children with allergic disease.
Publisher: Informa UK Limited
Date: 14-04-2016
DOI: 10.3109/07420528.2016.1167722
Abstract: Short naps on night shift are recommended in some industries. There is a paucity of evidence to verify the sustained recovery benefits of short naps in the last few hours of the night shift. Therefore, the current study aimed to investigate the sustained recovery benefits of 30 and 10-min nap opportunities during a simulated night shift. Thirty-one healthy participants (18F, 21-35 y) completed a 3-day, between-groups laboratory study with one baseline night (22:00-07:00 h time in bed), followed by one night awake (time awake from 07:00 h on day two through 10:00 h day three) with random allocation to: a 10-min nap opportunity ending at 04:00 h, a 30-min nap opportunity ending at 04:00 h or no nap (control). A neurobehavioral test bout was administered approximately every 2 h during wake periods. There were no significant differences between nap conditions for post-nap psychomotor vigilance performance after controlling for pre-nap scores (p > 0.05). The 30-min nap significantly improved subjective sleepiness compared to the 10-min nap and no-nap control (p < 0.05). The 10-min nap significantly worsened negative mood compared to the 30-min nap and no-nap control (p < 0.01). Contrary to some evidence suggesting "power naps" can help to alleviate performance decrements, a 30-min nap opportunity at approximately 04:00 h was found to improve subjective, but not objective sleepiness. A 10-min nap may lead to increased negative mood in the hours following the nap due to a "short nap aversion" effect.
Publisher: BMJ
Date: 04-2001
DOI: 10.1136/ARD.60.4.332
Abstract: Osteoarthritis (OA) is increasingly prevalent in the years after menopause. Epidemiological data suggest that the use of oestrogen replacement therapy (ERT) may protect against knee OA. To test the hypothesis that long term ERT (longer than five years) is associated with increased knee cartilage in postmenopausal women. The study involved 81 women (42 current users (> or = five years) of ERT and 39 who had never used it). Articular cartilage volumes were determined by processing images acquired in the sagittal plane using a T1 weighted fat suppressed magnetic resonance sequence on an independent work station. After bone size had been accounted for, ERT users had higher tibial cartilage volume than non-users. Total tibial cartilage volume was 7.7% (0.23 ml) greater in the group of ERT users (2.98 (0.47) ml mean (SD)) than in the untreated group (2.75 (0.50) ml). The difference, after adjustment for the significant explanatory factors (years since menopause, body mass index, age at menopause, and smoking), between the ERT users and non-users increased from 0.23 ml to 0.30 ml (95% confidence interval 0.08 to 0.52, p=0.008). These differences persisted after exclusion of women with OA. After adjustment for multiple confounders, women using long term ERT have more knee cartilage than controls. This may indicate that ERT prevents loss of knee articular cartilage.
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.AAP.2011.09.022
Abstract: There are many factors that may affect the sleep behaviour and subsequent fatigue risk of shift workers. In the Australian rail industry the emphasis is primarily on the impact of working time on sleep. The extent to which factors other than working time might affect the sleep behaviour of employees in the large and erse Australian rail industry is largely unknown. The present study used sleep, work and fatigue diaries completed for two weeks, in conjunction with actigraphy, to understand the contribution of demographic and health factors to sleep behaviour in 40 rail safety workers. Both shift type and having dependents were significant predictors of sleep duration (P<.05). Sleep duration was greatest prior to night shifts, followed by afternoon shifts and morning shifts. Participants with dependents got significantly less sleep than participants without dependents. Both timing of sleep and smoking were significant predictors of sleep quality (P<.05). Day sleeps were associated with lower subjective sleep quality than night sleeps and smokers reported poorer sleep quality than non-smokers. These findings indicate that factors other than working time have the potential to influence both the sleep duration and subjective sleep quality of rail safety workers.
Publisher: Scandinavian Journal of Work, Environment and Health
Date: 15-11-2021
DOI: 10.5271/SJWEH.3934
Publisher: BMJ
Date: 09-2007
Publisher: Springer Science and Business Media LLC
Date: 02-2008
DOI: 10.3758/BRM.40.1.347
Abstract: In this study, we evaluated the sensitivity of a 5-min personal digital assistant-psychomotor vigilance test (PDA-PVT) to severe sleep loss. Twenty-one participants completed a 10-min PVT-192 and a 5-min PDA-PVT at two hourly intervals during 62 h of sustained wakefulness. For both tasks, response speed and number of lapses (RTs > 500) per minute significantly increased with increasing hours of wakefulness. Overall, standardized response speed scores on the 5-min PDA-PVT closely tracked those of the PVT-192 however, the PDA-PVT was generally associated with more lapses/minute. Closer inspection of the data indicated that when the level of sleep loss and fatigue became more severe (i.e., Day 3), the 5-min PDA-PVT was not quite as sensitive as the 10-min PVT-192 when 2- to 10-sec foreperiods were used for both. It is likely, however, that the observed differences between the two devices was due to differences in task length. Thus, the findings provide further evidence of the validity of the 5-min PDA-PVT as a substitute for the 10-min PVT-192, particularly in circumstances in which a shorter test is required and/or the PVT-192 is not as practical.
Publisher: Research Square Platform LLC
Date: 22-04-2022
DOI: 10.21203/RS.3.RS-1582306/V1
Abstract: Background Hallux valgus is a common and disabling condition. This randomised pilot and feasibility trial aims to determine the feasibility of conducting a fully-powered parallel group randomised trial to evaluate the effectiveness of a multifaceted non-surgical intervention for reducing pain associated with hallux valgus. Methods Twenty-eight community-dwelling women with painful hallux valgus will be randomised to receive either a multifaceted, non-surgical intervention (footwear, foot orthoses, foot exercises, advice, and self-management) or usual care (advice and self-management alone). Outcome measures will be obtained at baseline, 4, 8 and 12 weeks. The primary outcome is feasibility, which will be evaluated according to demand, acceptability, adherence, adverse events, and retention rate. Limited efficacy testing will be conducted on secondary outcome measures including foot pain (the Manchester-Oxford Foot Questionnaire), foot muscle strength (hand-held dynamometry), general health-related quality of life (the Short Form-12), use of cointerventions, and participants’ perception of overall treatment effect. Biomechanical testing will be conducted at baseline to evaluate the immediate effects of the footwear/orthotic intervention on pressure beneath the foot and on the medial aspect of the first metatarsophalangeal joint and hallux. Discussion This study will determine the feasibility of conducting a fully-powered randomised trial of footwear, foot orthoses, foot exercises, advice and self-management for relieving pain associated with hallux valgus and provide insights into potential mechanisms of effectiveness.
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.AAP.2011.09.028
Abstract: Due to irregular working hours shiftworkers experience circadian disruption and sleep restriction. There is some evidence to indicate that these factors adversely affect health through changes in snacking behaviour. The aim of this study was to investigate the impact of sleep restriction, prior wake and circadian phase on snacking behaviour during a week of simulated shiftwork. Twenty-four healthy males (age: 22.0 ± 3.6 years, mean ± SD) lived in a sleep laboratory for 12 consecutive days. Participants were assigned to one of two schedules: a moderate sleep restriction condition (n=10) equivalent to a 6-h sleep opportunity per 24h or a severe sleep restriction condition (n=14) equivalent to a 4-h sleep opportunity per 24h. In both conditions, sleep/wake episodes occurred 4h later each day to simulate a rotating shiftwork pattern. While living in the laboratory, participants were served three meals and were provided with either five (moderate sleep restriction condition) or six (severe sleep restriction condition) snack opportunities daily. Snack choice was recorded at each opportunity and assigned to a category (sweet, savoury or healthy) based on the content of the snack. Data were analysed using a Generalised Estimating Equations approach. Analyses show a significant effect of sleep restriction condition on overall and sweet snack consumption. The odds of consuming a snack were significantly greater in the severe sleep restriction condition (P<0.05) compared to the moderate sleep restriction condition. In particular, the odds of choosing a sweet snack were significantly increased in the severe sleep restriction condition (P<0.05). Shiftworkers who are severely sleep restricted may be at risk of obesity and related health disorders due to elevated snack consumption and unhealthy snack choice. To further understand the impact of sleep restriction on snacking behaviour, future studies should examine physiological, psychological and environmental motivators.
Publisher: Public Library of Science (PLoS)
Date: 05-12-2018
Publisher: National Institute of Industrial Health
Date: 2015
Publisher: Wiley
Date: 12-03-2018
DOI: 10.1111/JSR.12682
Abstract: This study examined the associations between self-reported sleep timing and quality, and the frequency of breakfast and junk food consumption in 28,010 Australian school students (mean ± SD age = 13.3 ± 1.2 years, 51% male). After controlling for age, sex and socioeconomic status, regression analyses revealed that the odds of missing breakfast were significantly higher in children who reported poor sleep or later bedtimes, while the odds of junk food consumption were significantly higher in children reporting later weeknight bedtimes (p < 0.001). These findings suggest that sleep timing and quality influence the dietary choices of adolescents.
Publisher: Wiley
Date: 17-02-2014
DOI: 10.1002/ZOO.21120
Publisher: Research Square Platform LLC
Date: 13-04-2021
DOI: 10.21203/RS.3.RS-404837/V1
Abstract: Background: Abnormal infrapatellar fat pad (IPFP) plays a detrimental role in knee osteoarthritis (OA) by producing pro-inflammatory cytokines. IPFP may interact with synovium because of their adjacent anatomical positions however, whether abnormal IPFP can contribute to effusion-synovitis in knee OA is unclear.Methods: Among 255 knee OA patients, IPFP signal intensity alteration represented by four measurement parameters [standard deviation of IPFP signal intensity (IPFP sDev), upper quartile value of IPFP high signal intensity region (IPFP UQ (H)), ratio of IPFP high signal intensity region volume to whole IPFP volume (IPFP percentage (H)), and clustering factor of IPFP high signal intensity (IPFP clustering factor (H))] was measured quantitatively at baseline and two-year follow-up using magnetic resonance imaging (MRI). Effusion-synovitis of the suprapatellar pouch and other cavities were measured both quantitatively and semi-quantitatively as effusion-synovitis volume and effusion-synovitis score at baseline and two-year follow-up using MRI. Mixed-effects models were used to assess the associations between IPFP signal intensity alteration and effusion-synovitis over two years.Results: In multivariable analyses, all four parameters of IPFP signal intensity alteration were positively associated with total effusion-synovitis volume and effusion-synovitis volumes of the suprapatellar pouch and of other cavities over two years (all P <0.05). They were also associated with the semi-quantitative measure of effusion-synovitis except for IPFP percentage (H) with effusion-synovitis in other cavities. Conclusion: Quantitatively measured IPFP signal intensity alteration is positively associated with joint effusion-synovitis in people with knee OA, suggesting that IPFP signal intensity alteration may contribute to effusion-synovitis and a coexistent pattern of these two imaging biomarkers could exist in knee OA patients.
Publisher: Wiley
Date: 27-03-2018
DOI: 10.1111/JSR.12681
Abstract: Caffeine is known for its capacity to mitigate performance decrements. The metabolic side-effects are less well understood. This study examined the impact of cumulative caffeine doses on glucose metabolism, self-reported hunger and mood state during 50 hr of wakefulness. In a double-blind laboratory study, participants were assigned to caffeine (n = 9, 6M, age 21.3 ± 2.1 years body mass index 21.9 ± 1.6 kg/m
Publisher: BMJ
Date: 08-2003
Abstract: Biomedical studies are required to differentiate between the causes and results of knee osteoarthritis.
Publisher: Elsevier BV
Date: 09-2006
DOI: 10.1016/J.JOCA.2006.04.014
Abstract: Although knee alignment is associated with the progression of knee osteoarthritis (OA), it is unclear which features that characterize radiographic OA are related to alignment. The aim of this study was to examine the relationship between static knee joint alignment (measured as a continuous variable) and the radiographic features of knee OA (joint space narrowing and osteophytes). One hundred and twenty one adults with symptomatic knee OA were recruited using a combined strategy including referral from specialist centres, arthritis support groups and media advertising. X-rays were performed to classify the severity of disease and to determine static knee alignment. Increasing varus knee alignment was associated with increasing risk of medial compartment joint space narrowing (P < 0.001) and osteophytes (P = 0.005). Increasing valgus knee alignment was associated with an increased risk for lateral compartment joint space narrowing (P < 0.001) and osteophytes (P = 0.002). This study has demonstrated that the static knee angle, measured as a continuous variable, is an important determinant of the compartment-specific features of radiographic knee OA. Further work is required to determine whether interventions aimed at correcting these relatively minor levels of varus and valgus angulation will have an effect on the risk of tibiofemoral OA.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 21-04-2016
Publisher: BMJ
Date: 2022
DOI: 10.1136/BMJOPEN-2020-047888
Abstract: Approximately 40% of late-life dementia may be prevented by addressing modifiable risk factors, including physical activity and diet. Yet, it is currently unknown how multiple lifestyle factors interact to influence cognition. The ACTIVate Study aims to (1) explore associations between 24-hour time-use and diet compositions with changes in cognition and brain function and (2) identify duration of time-use behaviours and the dietary compositions to optimise cognition and brain function. This 3-year prospective longitudinal cohort study will recruit 448 adults aged 60–70 years across Adelaide and Newcastle, Australia. Time-use data will be collected through wrist-worn activity monitors and the Multimedia Activity Recall for Children and Adults. Dietary intake will be assessed using the Australian Eating Survey food frequency questionnaire. The primary outcome will be cognitive function, assessed using the Addenbrooke’s Cognitive Examination-III. Secondary outcomes include structural and functional brain measures using MRI, cerebral arterial pulse measured with diffuse optical tomography, neuroplasticity using simultaneous transcranial magnetic stimulation and electroencephalography, and electrophysiological markers of cognitive control using event-related potential and time frequency analyses. Compositional data analysis, testing for interactions between time point and compositions, will assess longitudinal associations between dependent (cognition, brain function) and independent (time-use and diet compositions) variables. The ACTIVate Study will be the first to examine associations between time-use and diet compositions, cognition and brain function. Our findings will inform new avenues for multidomain interventions that may more effectively account for the co-dependence between activity and diet behaviours for dementia prevention. Ethics approval has been obtained from the University of South Australia’s Human Research Ethics committee (202639). Findings will be disseminated through peer-reviewed manuscripts, conference presentations, targeted media releases and community engagement events. Australia New Zealand Clinical Trials Registry (ACTRN12619001659190).
Publisher: University of South Australia with SA Health and SafeWork SA
Date: 2017
DOI: 10.25954/NVKJ-TA75
Publisher: Bentham Science Publishers Ltd.
Date: 05-2006
Publisher: Elsevier BV
Date: 08-2021
DOI: 10.1016/J.SMRV.2021.101581
Abstract: The aim of this review was to explore the extent and nature of evidence exploring shiftwork and disruptions to cortisol. A systematic search was conducted across five databases: Medline, EMBASE, Psych INFO, Joanna Briggs Institute and PubMed between July-August 2020. Cortisol data were characterised into three main outcomes, 1) cortisol levels, 2) cortisol rhythm, and 3) cortisol awakening response (CAR) during shiftwork. Main findings demonstrate that shiftwork, especially night shift, significantly disrupts production of cortisol, the cortisol rhythm and CAR and, irregular shift schedules produce greater disruptions to cortisol than regular shift schedules. It was difficult to draw conclusions about the impact of shiftwork on movement of the cortisol rhythm and adaptation or recovery of the cortisol rhythm to and from night shift as the literature lacks consistency in definition of methods and variables. The present state of literature demonstrates cortisol levels, cortisol rhythm and the CAR are all disrupted by shiftwork, but there is a lack of consistency between studies on use of variables and most of the literature focuses on acute disruption rather than chronic effects. It will be important for future studies to investigate possible mechanisms that link shiftwork, disruptions to cortisol and chronic health conditions prevalent in shiftworkers.
Publisher: Research Square Platform LLC
Date: 18-05-2022
DOI: 10.21203/RS.3.RS-1663778/V1
Abstract: Aims: To investigate whether the associations between cartilage defects and cartilage volumes with changes in knee symptoms were mediated by osteophytes. Methods: Data from Vitamin D Effects on Osteoarthritis (VIDEO) study were analyzed as a cohort. Western Ontario and McMaster Universities Osteoarthritis Index was used to assess knee symptoms at baseline and follow-up. Osteophytes, cartilage defects and cartilage volumes were measured using magnetic resonance imaging at baseline. Associations between cartilage morphology and changes in knee symptoms were assessed using linear regression models, and mediation analysis was used to test whether these associations were mediated by osteophytes. Results: 334 participants (aged 50 to 79 years) with symptomatic knee osteoarthritis were included in the analysis. Cartilage defects were significantly associated with change in total knee pain, change in weight-bearing pain and change in non-weight-bearing pain after adjustment for age, sex, body mass index and intervention. Cartilage volume was significantly associated with change in weight-bearing pain and change in physical dysfunction after adjustment. Lateral tibiofemoral and patellar osteophyte mediated: the associations of cartilage defects with change in total knee pain (49%-55%) and change in weight-bearing pain (61%-62%) the association of cartilage volume with change in weight-bearing pain (27%-30%) and dysfunction (24%-25%). Both cartilage defects and cartilage volume had no direct effects on change in knee symptoms. Conclusions: The significant associations between cartilage morphology and changes in knee symptoms were indirect and were partly mediated by osteophytes.
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.SEMARTHRIT.2006.12.008
Abstract: To evaluate the relationship between serum testosterone (T), preandrogens and sex hormone binding globulin (SHBG), and the knee structure in middle-aged women without knee pain. One hundred and thirty-nine healthy women without knee pain, aged 40 to 67 years, underwent magnetic resonance imaging of their dominant knee to measure tibial and patella cartilage volumes and defects, respective bone area and volume, and bone marrow lesions. The serum level of T, preandrogens, and SHBG were analyzed using linear regression to determine whether associations existed between these hormones and knee structure. Free T and total T showed no association with cartilage volume or bone structures in the knee. SHBG showed a statistically positive association with patella bone volume after adjusting for confounders (P = 0.02). Our study suggests there are no associations between serum levels of T or the preandrogens and knee structure in women. The observed positive association between SHBG and patella bone volume may reflect a favorable effect of estrogen exposure on patella bone volume.
Publisher: MDPI AG
Date: 30-11-2016
DOI: 10.3390/NU8120771
Publisher: Cold Spring Harbor Laboratory
Date: 31-07-2021
DOI: 10.1101/2021.07.28.21261299
Abstract: Approximately 40% of late-life dementia may be prevented by addressing modifiable risk factors, including physical activity and diet. Yet, it is currently unknown how multiple lifestyle factors interact to influence cognition. The ACTIVate Study aims to 1) Explore associations between 24-hour time-use and diet compositions with changes in cognition and brain function and 2) Identify durations of time-use behaviours and the dietary compositions to optimise cognition and brain function. This three-year prospective longitudinal cohort study will recruit 448 adults aged 60-70 years across Adelaide and Newcastle, Australia. Time-use data will be collected through wrist-worn activity monitors and the Multimedia Activity Recall for Children and Adults (MARCA). Dietary intake will be assessed using the Australian Eating Survey food frequency questionnaire. The primary outcome will be cognitive function, assessed using the Addenbrooke’s Cognitive Examination-III (ACE-III). Secondary outcomes include structural and functional brain measures using Magnetic Resonance Imaging (MRI), cerebral arterial pulse measured with Diffuse Optical Tomography (Pulse-DOT), neuroplasticity using simultaneous Transcranial Magnetic Stimulation (TMS) and Electroencephalography (EEG), and electrophysiological markers of cognitive control using event-related potential (ERP) and time-frequency analyses. Compositional data analysis, testing for interactions between time-point and compositions, will assess longitudinal associations between dependent (cognition, brain function) and independent (time-use and diet compositions) variables. The ACTIVate Study will be the first to examine associations between time-use and diet compositions, cognition and brain function. Our findings will inform new avenues for multidomain interventions that may more effectively account for the co-dependence between activity and diet behaviours for dementia prevention. Ethics approval has been obtained from University of South Australia’s Human Research Ethics committee (202639). Findings will be disseminated through peer reviewed manuscripts, conference presentations, targeted media releases and community engagement events. Australia New Zealand Clinical Trials Registry (ACTRN12619001659190). The ACTIVate Study will collect comprehensive measures of lifestyle behaviours and dementia risk over time in 448 older adults aged 60-70 years. Using newly developed Compositional Data Analysis (CoDA) techniques we will examine the associations between time-use and diet compositions, cognition and brain function. Data will inform the development of a digital tool to help older adults obtain personalised information about how to reduce their risk of cognitive decline based on changes to time use and diet. Recruitment will be focussed on older adults to maximise the potential of making an impact on dementia prevention in the next 10 years. Findings may not be generalisable to younger adults.
Publisher: Informa UK Limited
Date: 15-05-2018
DOI: 10.1080/07420528.2018.1466798
Abstract: Two of the most ubiquitous fatigue countermeasures used by shift-working nurses are napping and caffeine. This mixed-methods case study investigated the ways nurses and midwives utilised napping and caffeine countermeasures to cope with shift work, and associated sleep, physical health and psychological health outcomes. N = 130 Australian shift-working nurses and midwives (mean age = 44 years, range = 21-67, 115F, 15M) completed the Standard Shiftwork Index. A sub-set of 22 nurses and midwives completed an in-depth interview. Nearly 70% of participants reported napping. Those who napped during night shifts had significantly less total sleep time before (F This study identified reasons shift workers chose to engage in or abstain from napping and consuming caffeine, and how these strategies related to poor sleep and health outcomes. Further research is required to help develop recommendations for shift workers regarding napping and caffeine consumption as fatigue countermeasures, whilst taking into account the associated hazards of each strategy.
Publisher: Elsevier BV
Date: 08-2005
DOI: 10.1016/J.JOCA.2005.04.009
Abstract: Although the current recommendation is to measure radiographic joint space width (JSW) to assess structural change in osteoarthritis (OA), there is increasing interest in direct measurement of cartilage volume from magnetic resonance imaging (MRI). We performed a longitudinal study to compare change in both JSW and articular cartilage volume in subjects with symptomatic knee OA. JSW was measured in 28 subjects with knee OA (57% females, mean age 62.8+/-9.8 years) who had standing radiographs in full extension, where both radiographs had satisfactory alignment. Each subject had femoral, tibial and combined femoral and tibial cartilage volumes determined from T1-weighted fat saturated sagittal knee MRI. All subjects had a repeat of the knee radiograph and MRI 1.96+/-0.4 years later. At baseline there was a moderate, but statistically significant, correlation between JSW and femoral and tibial cartilage volumes in the medial tibiofemoral joint, which was strengthened by adjusting for medial tibial bone size (R=0.58-0.66, P=0.001). Although we observed a reduction in JSW and femoral and tibial cartilage volumes over the study period, there was no significant association between reduction in JSW and cartilage volume (R<0.13). There was a trend towards a significant association between change in medial tibiofemoral cartilage volume and joint replacement at 4 years (OR=9.0, P=0.07) but not change in medial tibiofemoral JSW (OR=1.1, P=0.92). Although there was a modest correlation between cartilage volume and JSW in the medial tibiofemoral compartment, there was no correlation between longitudinal change in these measures. Change in cartilage volume appears to be a better predictor of joint replacement. Further work in larger s les over a longer period of time will be needed to confirm these findings.
Publisher: Elsevier BV
Date: 10-2000
DOI: 10.1016/S1053-2498(00)00175-3
Abstract: To study the clinical impact of gout treatment following cardiac transplantation. We performed an audit of all cardiac transplant recipients of the Alfred Hospital before August 1998 who lived in Victoria. We studied 225 patients (81% men), with a mean post-transplant follow-up of 50.8 months (SD 36). Forty-three (19%) had pre-transplant gout, 19 recurring post-transplantation. Twenty-three patients developed gout de novo. Of the 24 patients who received allopurinol, 6 developed pancytopenia and required hospitalization. Fourteen received a change in immunosuppression: in 5 patients following pancytopenia, and in 9 to enable safe use of allopurinol. Thirty-two patients received colchicine 5 developed neuromyopathy. Impaired renal function, diuretic use, and hypertension were more common in this sub-group. Non-steroidal anti-inflammatory agents, used in 16 patients, caused serious complications in 1 patient (life-threatening peptic ulceration and hemorrhage, precipitating dialysis-dependent chronic renal failure). Cardiac transplant recipients, when treated for gout, are at high risk of therapeutic complications. Thus, gout treatment significantly affects care, health, and immunosuppression of these patients.
Publisher: Elsevier BV
Date: 06-2005
DOI: 10.1016/S1440-2440(05)80009-X
Abstract: Appropriate management of scaphoid fractures is important because of the risk of long-term complications such as delayed or non-union, pain and disability. Up to 25% of scaphoid fractures are not visible on the initial radiographs. Consequently, all clinically suspected scaphoid fractures are treated as fractures with cast immobilisation until cause of the symptoms is clarified. The diagnosis often utilises a number of second line investigations that are generally performed 10-14 days after the injury. Bone scintigraphy is currently the most commonly used of these as it rarely misses a fracture. However, it does not visualise anatomical structure and therefore alternative diagnoses are difficult. Magnetic resonance imaging (MRI) is at least as sensitive and more specific than bone scanning and has the advantages of being able to identify other lesions and not expose the patient to any radiation. Furthermore, the scan may be performed as early as 2.8 days following an injury rather than 10 days later in the case of a bone scan. Although the cost of MRI is higher than other imaging modalities, it may be cost-effective in the overall management of patients with occult scaphoid fractures since it may prevent unnecessary cast immobilisation in active people. The most appropriate method of cast immobilisation is presently unclear but evidence exists for improved clinical outcomes in those that have both the thumb and elbow immobilised for the first six weeks.
Publisher: Wiley
Date: 08-2002
DOI: 10.1002/ART.10460
Abstract: The rate of change in osteoarthritic (OA) tibial articular cartilage and the factors that influence it are not known. We examined a cohort of subjects with OA to determine the change in articular knee cartilage volume over the course of 2 years and to identify factors which might influence such change and its rate. One hundred twenty-three subjects with OA underwent baseline knee radiography and magnetic resonance imaging (MRI) on their symptomatic knee. They were followed up 2 years later with a repeat MRI of the same knee. Knee cartilage volume was measured at baseline and at followup. Risk factors assessed at baseline were tested for their association with change in knee cartilage volume over time. Mean +/- SD total tibial articular cartilage decreased by 5.3 +/- 5.2% (95% confidence interval [95% CI] 4.4%, 6.2%) per year. The annual percentages of loss of medial and lateral tibial cartilage were 4.7 +/- 6.5% (95% CI 3.6%, 5.9%) and 5.3 +/- 7.2% (95% CI 4.1%, 6.6%), respectively. Initial cartilage volume was the most significant determinant of loss of tibial cartilage in all compartments, while age was a significant determinant of lateral tibial cartilage loss, when possible confounders were accounted for. In OA, tibial cartilage volume is lost at a rate of approximately 5% per year. The main factor affecting cartilage loss is initial cartilage volume. Our results suggest that cartilage loss may be more rapid early in disease. Further study is required to determine whether the rate of cartilage loss in OA is steady or phasic, and to identify factors amenable to intervention to reduce cartilage loss.
Publisher: Informa UK Limited
Date: 05-02-2004
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.APERGO.2018.01.002
Abstract: While many countries have dual-driver ("two-up") modes in freight rail, driver shortage creates increasing pressure to move to single-driver operations. While this change has implications for workload and safety, the roles of the primary and second drivers have not been systematically mapped. This mapping is the focus of this paper, which presents a hierarchical task analysis (HTA) from a multi-methods study (n = 40). Results indicated that transitioning from two-up to single driver operations will result in substantial changes in physical and cognitive workload for the remaining driver. These changes go much further than the simple loss of a crew-mate to double-check or verify actions and cues. This HTA can form the basis of an evidence-based safety case for the change from two-up to single-driver operations, as well as a platform for considering mechanisms to maintain safety and productivity for the now solo train driver.
Publisher: Elsevier BV
Date: 04-2005
Publisher: Oxford University Press (OUP)
Date: 06-01-2004
Publisher: Oxford University Press (OUP)
Date: 27-09-2006
DOI: 10.1093/RHEUMATOLOGY/KEI108
Abstract: Cartilage defects are present in subjects with knee osteoarthritis (OA). Although they are often present in healthy subjects, there is little data on the natural history of cartilage defects. The aim of this study was to examine the change in cartilage defects over 2 yr and to identify factors associated with this change. One hundred and twenty-four healthy subjects underwent magnetic resonance imaging of their dominant knee at baseline and follow-up. Cartilage defects were scored (0-4) at five sites. Bone size was determined at medial and lateral tibial plateau and patella. Height, weight, body mass index and physical activity were measured by standard protocols. Eighty-six subjects completed the study. The mean cartilage defect score of each tibiofemoral compartment increased over time. However, medial and lateral tibiofemoral defect score decreased in 5% of the subjects. Cartilage defects were more likely to progress in males than females in each in idual compartment (P<0.001 for medial tibiofemoral, P=0.005 for lateral tibiofemoral and P=0.01 for patellar cartilage). Baseline cartilage defect score was negatively associated with the progression of cartilage defects in each compartment (all P<0.001). Although knee cartilage defects progressed over time in the majority of normal subjects, those of the highest severity tended to regress. Male gender and baseline cartilage defect score were the main factors associated with the progression of cartilage defects. Larger studies will be required to identify factors associated with the progression and regression of lesions.
Publisher: National Institute of Industrial Health
Date: 2005
Abstract: Fatigue is an increasingly recognised risk factor for transportation accidents. In light of this, there is the question of whether driving whilst fatigued should be a criminal offence. This paper discusses the current legal position, including the problems of voluntary conduct and self awareness. Three models for reform are proposed. The manner in which scientific research can inform legal consideration and future directions for research are discussed.
Publisher: Informa UK Limited
Date: 31-03-2011
Publisher: Elsevier BV
Date: 02-2019
DOI: 10.1016/J.SLEH.2018.10.008
Abstract: Social media interactions via email and instant messaging (E/IM) are common in children and adolescents and may lead to insufficient sleep. This study investigated associations between high-frequency E/IM use to interact with peers, perceived insufficient sleep, and reduced time in bed (TIB) in female children and adolescents. The Children's Report of Sleep Patterns was completed by 189 female primary and secondary school students (8-16 years old). Responses were categorized as binary variables (high-frequency use vs not high-frequency use right amount of sleep vs too little sleep), and TIB was calculated from bed and wake times for the previous 24 hours. High-frequency social media interactions using E/IM during the hour before bed were significantly associated with perceived insufficient sleep (odds ratio [confidence interval]: 2.68 [1.39-5.17]) but not with reduced TIB (-19.07 [-40.02 to 1.89]). High-frequency social media interactions using E/IM in the hour before bed are a potentially modifiable risk factor for insufficient sleep in female students. Strategies to reduce nighttime usage may improve sleep in children and adolescents.
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.APERGO.2015.12.004
Abstract: Shorter, more frequent rosters, such as 6h-on/6h-off split shifts, may offer promise to sleep, subjective sleepiness and performance by limiting shift length and by offering opportunities for all workers to obtain some sleep across the biological night. However, there exists a paucity of studies that have examined these shifts using objective measures of sleep and performance. The present study examined neurobehavioural performance, sleepiness and sleep during 6h-on/6h-off split sleep schedules. Sixteen healthy adults (6 males, 26.13 y ± 4.46) participated in a 9-day laboratory study that included two baseline nights (BL, 10h time in bed (TIB), 2200 h-0800 h), 4 days on one of two types of 6h-on/6h-off split sleep schedules with 5h TIB during each 'off' period (6h early: TIB 0300 h-0800 h and 1500 h-20000 h, or 6-h late: TIB 0900 h-1400 h and 2100 h-0200 h), and two recovery nights (10h TIB per night, 2200 h-0800 h). Participants received 10h TIB per 24h in total across both shift schedules. A neurobehavioural test bout was completed every 2 h during wake, which included the Psychomotor Vigilance Task (PVT) and the Karolinska Sleepiness Scale (KSS). Linear mixed effects models were used to assess the effect of day (BL, shift days 1-4), schedule (6h early, 6h late) and trial (numbers 1-6) on PVT lapses (operationalised as the number of reaction times >500 ms), PVT total lapse time, PVT fastest 10% of reaction times and KSS. Analyses were also conducted examining the effect of day and schedule on sleep variables. Overall, PVT lapses and total lapse time did not differ significantly between baseline and shift days, however, peak response speeds were significantly slower on the first shift day when compared to baseline, but only for those in the 6h-late condition. Circadian variations were apparent in performance outcomes, with in iduals in the 6h-late condition demonstrated significantly more and longer lapses and slower peak reaction times at the end of their night shift (0730 h) than at any other time during their shifts. In the 6h-early condition, only response speed significantly differed across trials, with slower response speeds occurring at trial 1 (0930 h) than in trials 3 (1330 h) or 4 (2130 h). While subjective sleepiness was higher on shift days than at baseline, sleepiness did not accumulate across days. Total sleep was reduced across split sleep schedules compared to baseline. Overall, these results show that while there was not a cumulative cost to performance across days of splitting sleep, participants obtained less sleep and reported lowered alertness on shift days. Tests near the circadian nadir showed higher sleepiness and increased performance deficits. While this schedule did not produce cumulative impairment, the performance deficits witnessed during the biological night are still of operational concern for industry and workers alike.
Publisher: Elsevier BV
Date: 02-2021
Publisher: Frontiers Media SA
Date: 24-11-2022
DOI: 10.3389/FNHUM.2022.1051793
Abstract: Physical activity, sedentary behaviour and sleep are associated with cognitive function in older adults. However, these behaviours are not independent, but instead make up exclusive and exhaustive components of the 24-h day. Few studies have investigated associations between 24-h time-use composition and cognitive function in older adults. Of these, none have considered how the quality of sleep, or the context of physical activity and sedentary behaviour may impact these relationships. This study aims to understand how 24-h time-use composition is associated with cognitive function across a range of domains in healthy older adults, and whether the level of recreational physical activity, amount of television (TV) watching, or the quality of sleep impact these potential associations. 384 healthy older adults (age 65.5 ± 3.0 years, 68% female, 63% non-smokers, mean education = 16.5 ± 3.2 years) participated in this study across two Australian sites (Adelaide, n = 207 Newcastle, n = 177). Twenty-four-hour time-use composition was captured using triaxial accelerometry, measured continuously across 7 days. Total time spent watching TV per day was used to capture the context of sedentary behaviours, whilst total time spent in recreational physical activity was used to capture the context of physical activity (i.e., recreational accumulation of physical activity vs. other contexts). Sleep quality was measured using a single item extracted from the Pittsburgh Sleep Quality Index. Cognitive function was measured using a global cognition index (Addenbrooke’s Cognitive Examination III) and four cognitive domain composite scores (derived from five tests of the Cambridge Neuropsychological Test Automated Battery: Paired Associates Learning One Touch Stockings of Cambridge Multitasking Reaction Time Verbal Recognition Memory). Pairwise correlations were used to describe independent relationships between time use variables and cognitive outcomes. Then, compositional data analysis regression methods were used to quantify associations between cognition and 24-h time-use composition. After adjusting for covariates and false discovery rate there were no significant associations between time-use composition and global cognition, long-term memory, short-term memory, executive function, or processing speed outcomes, and no significant interactions between TV watching time, recreational physical activity engagement or sleep quality and time-use composition for any cognitive outcomes. The findings highlight the importance of considering all activities across the 24-h day against cognitive function in older adults. Future studies should consider investigating these relationships longitudinally to uncover temporal effects.
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.APERGO.2010.06.010
Abstract: The purpose of the current study was to investigate the impact of work- and sleep-related factors on an objective measure of response time in a field setting. Thirty-five mining operators working 12-h shift patterns completed daily sleep and work diaries, wore activity monitors continuously and completed palm-based psychomotor vigilance tests (palmPVT) at the start and end of each shift. Linear mixed models were used to test the main effects on response time of roster, timing of test, sleep history and prior wake. The time at which the test occurred was a significant predictor of response time (F₃(,)₄₀₃(.)₄ = 6.72, p < .01) with the end of night shifts being associated with significantly slower response times than the start of night shifts, and the start or end of day shifts. Further, the amount of sleep obtained in the 24h prior to the test was also a significant predictor of response time (F₃(,)₄₀₇(.)₀ = 3.05, p < .01). The results suggest that, as expected, the end of night shift is associated with changes in response time indicative of performance impairments. Of more interest however is that immediate sleep history was also predictive of changes in response time with lower amounts of prior sleep related to slower response times. The current data provides further evidence that sleep is a primary mediator of performance, independent of roster pattern.
Publisher: Wiley
Date: 15-05-2017
DOI: 10.1002/JCLP.22485
Abstract: Little is known about the personal factors that increase vulnerability to job-related stress and burnout among psychologists in training. This study was based on a large international s le and aimed to explore the role of early maladaptive schemas (EMS) in predicting vulnerability to burnout, as well as attendant effects on short-term physical health, in clinical and counseling postgraduate psychology trainees. An online, quantitative, cross-sectional survey method design was used to collect self-report data that measured burnout, EMS, and physical health from 1,297 trainees. Only the unrelenting standards (US) schema predicted high burnout among trainees. The most commonly endorsed physical health symptoms were back and neck pain and tiredness, and were more severe for those experiencing high burnout. The current study contributes to our understanding of the role of the US EMS in the evolution of burnout in trainees and has implications for the development of self-awareness training programs for this population.
Publisher: Wiley
Date: 28-06-2005
DOI: 10.1002/ART.21148
Abstract: The significance of asymptomatic knee cartilage defects in healthy in iduals is not known. The aim of this study was to examine the association between cartilage defects in the knee and cartilage volume both cross-sectionally and longitudinally in healthy, middle-age adults. Eighty-six healthy men and women (mean +/- SD age 53.8 +/- 8.8 years) underwent T1-weighted fat-suppressed magnetic resonance imaging of their dominant knees at baseline and at the 2-year followup visit. Knee cartilage volume was measured. Cartilage defects were scored according to a grading system (0-4) and as present (a defect score of > or = 2) or absent in the medial and lateral tibiofemoral compartments. Cartilage defects in the medial and lateral tibiofemoral compartments were very common (in 61% and 43% of subjects, respectively). Those with cartilage defects had a 25% reduction in medial tibial cartilage volume, a 15% reduction in lateral tibial cartilage volume, and a 19% reduction in total femoral cartilage volume relative to those with no cartilage defects in cross-sectional analyses (all P < 0.05). In the medial tibiofemoral compartment, the annual loss of tibial cartilage in those with cartilage defects was 2.5% (95% confidence interval [95% CI] 2.2%, 3.1%) compared with an annual loss of tibial cartilage of 1.3% (95% CI 0.5%, 2.0%) in those with no defects (P = 0.028), independent of other known risk factors for osteoarthritis (OA). These data suggest that the presence of asymptomatic, non-full-thickness medial tibiofemoral cartilage defects identifies healthy in iduals most likely to lose knee cartilage in the absence of radiographic knee OA. Thus, interventions aimed at reducing or reversing cartilage defects may reduce the risk of subsequent knee OA.
Publisher: Elsevier BV
Date: 2005
DOI: 10.1016/J.MEHY.2005.02.026
Abstract: Obesity and the female sex represent significant risk factors for osteoarthritis (OA). Few studies have demonstrated a metabolic link between obesity and OA, strengthening the likelihood that biomechanical factors mediate this relationship, possibly via the redistribution of increased body mass to weight-bearing joints. However, it is less plausible that the biomechanical factors that contribute toward the incidence of OA at weight-bearing joints, such as the knee, are similar to those at non-weight bearing joints, such as in the hand. This may suggest that non-examined or unidentified biomechanical and/or systemic factors may be important contributors to the aetiology of OA. Recent developments that have helped to better appreciate the pathophysiology of obesity offer new hope to understanding the link between obesity and OA. The discovery of the obesity gene (ob) and its product leptin may have important implications for the onset and progression of OA. For instance, the greater total body fat of the average adult female may partially account for the gender disparity toward OA, given that females theoretically demonstrate higher levels of adipose derived systemic leptin concentrations than their male counterparts. However, while it was previously thought that adipose cells were only capable of leptin production, osteoblasts and chondrocytes are also capable of leptin synthesis and secretion, inferring that local leptin production may be of great importance. For instance, significant levels of leptin were observed in the cartilage and osteophytes of people with OA, yet few chondrocytes produced leptin in the cartilage of healthy people. Leptin has also been demonstrated to induce anabolic activity in the chondrocytes of rats, which may ultimately confer structural joint changes. This paper hypothesizes that leptin may be an unexamined systemic or local factor that may mediate the metabolic link between obesity and OA and partially account for the gender disparity toward the disease.
Publisher: Oxford University Press (OUP)
Date: 16-12-2013
Publisher: BMJ
Date: 10-2001
Abstract: Despite the increasing interest in using knee cartilage volume as an outcome measure in studies of osteoarthritis (OA), it is unclear what components of knee cartilage will be most useful as markers of structure in the tibiofemoral (TF) joint. To compare the changes that occur in femoral and tibial cartilage volume in normal and osteoarthritic knees and how they relate to radiological grade. 82 subjects (44 female, 38 male, age range 35-69 years) with a spectrum of radiological knee OA were examined. Each subject had femoral and tibial cartilage volume in the medial and lateral TF joint determined from T(1) weighted fat saturated magnetic resonance images of the knee. Radiological grade of OA was determined from standing knee radiographs. There was strong correlation between femoral and tibial cartilage volume measured in both the medial (R=0.75, p<0.001) and lateral TF joint (R=0.77, p<0.001). Similar correlations persisted when those with normal and those with OA joints were examined separately at both the medial and lateral TF joint. For each increase in radiological grade of joint space narrowing (0-3), there was a mean (SD) reduction in tibial cartilage volume of 1.00 (0.32) ml in the medial compartment and 0.53 (0.25) ml in the lateral compartment, after adjusting for differences in bone size. Similar changes were seen in the femoral cartilage. The amounts of tibial and femoral cartilage are strongly related. It may be that for TF joint disease, measuring tibial cartilage alone may be adequate, given that measurements of the total femoral cartilage are less reproducible and the difficulties inherent in identifying the most appropriate component of femoral cartilage to measure.
Publisher: Informa UK Limited
Date: 2006
DOI: 10.1080/07420520601096393
Abstract: In recent years, there has been increasing interest in the use of bio-mathematical models to predict alertness, performance, and/or fatigue in operational settings. Current models use only biological factors to make their estimations, which can be limited in operational settings where social and geo-physical factors also dictate when sleep occurs. The interaction between social and biological factors that help determine the timing and duration of sleep during layover periods have been investigated in order to create and initially validate a mathematical model that may better predict sleep in the field. Participants were 32 male transmeridian airline pilots (17 captains, 10 first officers, and 5 second officers) flying the Sydney-Bangkok-London-Singapore-Sydney (SYD-LHR) pattern. Participants continued their regular schedule while wearing activity monitors and completing sleep and work diaries. The theoretical sleep timing model underpinning this analysis consists of separate formulations for short ( 32 h) break periods. Longer break periods are split into three distinct phases-recovery (break start until first local night), personal (first local night until last local night), and preparation phases (last local night until break end)-in order to exploit potential differences specific to each. Furthermore, an iterative procedure combining prediction and retrodiction (i.e., using future duty timing information to predict current sleep timing) was developed to optimize predictive ability. Analysis found an interaction between the social and circadian sleep pressures that changed over the break period. Correlation analysis indicated a strong relationship between the actual sleep and new model's predictions (r = 0.7-0.9), a significant improvement when compared to existing models (r = 0.1-0.4). Social and circadian pressures play important roles in regulating sleep for international flight crews. An initial model has been developed in order to regulate sleep in these crews. The initial results have shown promise when applied to small sets of data however, more rigorous validation must be carried out.
Publisher: Elsevier
Date: 2017
Publisher: Informa UK Limited
Date: 12-2013
Publisher: Springer Science and Business Media LLC
Date: 12-11-2019
Publisher: Elsevier BV
Date: 06-2011
DOI: 10.1016/J.APERGO.2010.06.014
Abstract: A number of studies have described mood change during sleep loss in the laboratory, however, an understanding of fluctuations in structural aspects of mood under such conditions is lacking. Sixty-two healthy young adults completed one of three possible conditions: one (n = 20) or two (n = 23) nights of sleep loss or the control condition which consisted of one (n = 9) or two (n = 10) nights of 9 h time in bed. The Mood Scale II was completed every two waking hours and data were analysed in terms of the frequency and intensity of mood reports. Overall, sleep loss conditions were associated with significantly less frequent happiness and activation and more frequent fatigue reports (p < 0.001). Intensity was also significantly reduced for activation and happiness, and increased for depression, anger and fatigue (p < 0.05). Interestingly, there were no significant differences in anger following two nights in the laboratory with or without sleep. Further, two nights in the lab with normal sleep was associated with significant increases in depression intensity (p < 0.05). Findings support the hypothesis of a mood regulatory function of sleep and highlight the relative independence of frequency and intensity and of positive and negative mood dimensions. Findings also suggest that the laboratory environment, in the absence of sleep loss, may have a significant negative impact on mood.
Publisher: Research Square Platform LLC
Date: 30-03-2020
Abstract: Background: To examine the associations between hip muscle cross-sectional area and hip pain and function in community-based in iduals with mild-to-moderate hip osteoarthritis. Methods: This study included 27 participants with mild-to-moderate hip osteoarthritis. Cross-sectional area of hip muscles, including psoas major, rectus femoris, gluteus maximus, gluteus medius and minimus, adductor longus and magnus, obturator internus, and obturator externus, were measured from magnetic resonance images. Hip pain and function were evaluated using the Hip Disability and Osteoarthritis Outcome Score (HOOS) categorised into 5 subscales: pain, symptoms, activity of daily living, sport and recreation function, and hip-related quality of life (for each subscale 0 representing extreme problems and 100 representing no problems). Results: Mean age of the 27 participants was 63.2 (SD 7.6) years and 66.7% (n=18) were female. After adjusting for age and gender, greater cross-sectional area of adductor longus and magnus was associated with a higher HOOS score in quality of life (regression coefficient 1.4, 95% confidence interval (CI) 0.2-2.7, p=0.02), activity of daily living (regression coefficient 1.3, 95% CI 0.1-2.6, p=0.04) and sport and recreation function (regression coefficient 1.6, 95% CI 0.1-3.0, p=0.04). There was a trend towards an association between greater cross-sectional area of psoas major and a higher quality of life score (regression coefficient 3.6, 95% CI -0.5 to 7.7, p=0.08). The cross-sectional area of hip muscles was not significantly associated with HOOS pain or symptom score. Conclusion: Greater cross-sectional area of hip adductors was associated with better function and quality of life in in iduals with mild-to-moderate hip osteoarthritis. Greater cross-sectional area of hip flexors might be associated with better quality of life. These findings, while need to be confirmed in longitudinal studies, suggest that targeting the hip adductor and flexor muscles may improve function and quality of life in those with mild-to-moderate hip osteoarthritis.
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.MATURITAS.2019.04.204
Abstract: As the number of older people increases, so too does the prevalence of neurodegenerative disease. Worldwide, health organisations have identified the need for practical, affordable interventions to slow or delay the onset of neurodegenerative diseases such as dementia, for which there are multiple modifiable risk factors. The effects of various interventions on brain health has been investigated, including achieving sufficient physical activity, getting appropriate amounts and quality of sleep, and limiting sedentary behaviours. Few of these studies, though, have taken into account more than one lifestyle behaviour within a single study. Epidemiologists have recently initiated a paradigm shift to move away from studying the independent effects of each physical activity, sleep and sedentary behaviour, and towards an integrated 24-h time-use paradigm. Time is finite, and thus to increase time in one activity (for ex le physical activity), equal time must be taken away from other activities (sleep and sedentary behaviour). This 24-h time-use paradigm has begun to be used when studying obesity, adiposity and quality of life however, to the authors' knowledge, it has not yet been adopted by cognitive neuroscientists for the study of cognition or brain function. This narrative review synthesises the evidence for the neurophysiological effects of physical activity, sleep and sedentary behaviour independently, with a particular focus on brain structure, function and neurodegenerative disease risk. Then, we conclude with a call to action, addressing the need for studies to move towards an integrated 24-h time-use paradigm.
Publisher: Research Square Platform LLC
Date: 23-01-2020
Abstract: Objective: To examine the associations between hip muscle cross-sectional area and hip pain and function in community-based in iduals with mild-to-moderate hip osteoarthritis. Methods: This study included 27 participants with mild-to-moderate hip osteoarthritis. Cross-sectional area of hip muscles, including psoas major, rectus femoris, gluteus maximus, gluteus medius and minimus, adductor longus and magnus, obturator internus, and obturator externus, were measured from magnetic resonance images. Hip pain and function were evaluated using the Hip Disability and Osteoarthritis Outcome Score (HOOS). Results: After adjusting for age and gender, greater cross-sectional area of adductor longus and magnus was associated with a higher HOOS score in quality of life (regression coefficient 1.4, 95% confidence interval (CI) 0.2-2.7, p=0.02), activity of daily living (regression coefficient 1.3, 95% CI 0.1-2.6, p=0.04) and sport and recreation function (regression coefficient 1.6, 95% CI 0.1-3.0, p=0.04). Greater cross-sectional area of psoas major was associated with a higher quality of life score (regression coefficient 3.6, 95% CI -0.5 to 7.7, p=0.08). The cross-sectional area of hip muscles was not significantly associated with HOOS pain or symptom score. Conclusion: Greater cross-sectional area of hip adductors was associated with better function and quality of life in in iduals with mild-to-moderate hip osteoarthritis. Greater cross-sectional area of hip flexors might be associated with better quality of life. These findings, while need to be confirmed in longitudinal studies, suggest that targeting the hip adductor and flexor muscles may improve function and quality of life in those with mild-to-moderate hip osteoarthritis.
Publisher: Springer Science and Business Media LLC
Date: 07-2013
DOI: 10.1111/SBR.12023
Publisher: Elsevier BV
Date: 05-2006
DOI: 10.1016/J.JSAMS.2006.03.011
Abstract: Isolating the particular joints/limb segments associated with knee adductor moment variability may provide clinically important data that could help to identify strategies to reduce medial tibiofemoral joint load. The aim of this study was to examine whether or not foot and thigh rotation during human locomotion are significant determinants of knee adductor moment variability. Three-dimensional gait analyses were performed on 32 healthy adult women (mean age 54+/-12 years, mean BMI 25+/-4 kg m(-2)) with radiologically normal knees. The relationships between foot rotation, thigh rotation and the external knee adduction moment were examined during early and late-stance phases of the gait cycle. The degree of foot rotation correlated significantly with the magnitude of the peak knee adduction moment during late stance (r=0.40, p=0.024). No significant associations were apparent between thigh rotation and the peak knee adduction moment. The association between foot rotation and the knee adduction moment in this study suggests that women who walk with external rotation at the foot reduce their knee adduction moment during late stance. This result implies that changes in foot kinematics can modify the medial tibiofemoral load during gait, which may be important in the prevention and management of knee osteoarthritis.
Publisher: Springer Science and Business Media LLC
Date: 05-2004
DOI: 10.3758/BF03195580
Abstract: The 10-min psychomotor vigilance task (PVT) has often been used to assess the impact of sleep loss on performance. Due to time constraints, however, regular testing may not be practical in field studies. The aim of the present study was to examine the suitability of tests shorter than 10 min. in duration. Changes in performance across a night of sustained wakefulness were compared during a standard 10-min PVT, the first 5 min of the PVT, and the first 2 min of the PVT. Four performance metrics were assessed: (1) mean reaction time (RT), (2) fastest 10% of RT, (3) lapse percentage, and (4) slowest 10% of RT. Performance during the 10-min PVT significantly deteriorated with increasing wakefulness for all metrics. Performance during the first 5 min and the first 2 min of the PVT deteriorated in a manner similar to that observed for the whole 10-min task, with all metrics except lapse percentage displaying significant impairment across the night. However, the shorter the task s ling time, the less sensitive the test is to sleepiness. Nevertheless, the 5-min PVT may provide a viable alternative to the 10-min PVT for some performance metrics.
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.NEDT.2015.05.017
Abstract: Nurses are often the first point of contact for patients hospitalized due to alcohol-related causes. Alcohol dependence is highly stigmatized and as a result healthcare professionals often have low behavioural intentions, meaning low willingness to care for these patients. This can have a direct influence on quality of care. The purpose of this study was to explore enrolled nursing students' intention to care for patients with alcohol dependence and the antecedents, preliminary factors, that predict this within the Theory of Planned Behaviour specifically attitudes, subjective norms, self-efficacy and controllability. The study was a cross-sectional survey using the Theory of Planned Behaviour. Two Technical and Further Education South Australia c uses across metropolitan Adelaide. n=86 enrolled nursing students completed the survey (62% response rate). Enrolled nursing students' intention, attitudes, subjective norms, self-efficacy and controllability were measured using a Theory of Planned Behaviour Questionnaire. The Short Alcohol and Alcohol Problems Perception Questionnaire investigated attitudes in more detail and a short knowledge scale assessed alcohol-related knowledge. Subjective norms and attitudes had a significant, positive effect on intention to care within the final model, accounting for 22.6% of the variance, F2,83=12.12, p<0.001. Subjective norms were the strongest predictor. External factors such as age, previous alcohol training and alcohol-related knowledge held direct paths to antecedents of intention. Subjective norms were the strongest predictor of intention to care for patients with alcohol dependence, followed by attitudes. The study provides an understanding of enrolled nursing students' intention to care for alcohol dependent patients. These findings can assist in developing tailored alcohol training for students, to increase attitudes and foster behavioural change, in order to improve the quality of care for these patients.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.PSYNEUEN.2017.01.028
Abstract: During sleep deprivation, neurobehavioral functions requiring sustained levels of attention and alertness are significantly impaired. Discrepancies between subjective measures of sleepiness and objective performance during sustained operations have led to interest in physiological monitoring of operator performance. Alertness, vigilance, and arousal are modulated by the wake-promoting actions of the central noradrenergic system. Salivary alpha-amylase (sAA) has been proposed as a sensitive peripheral measure of noradrenergic activity, but limited research has investigated the relationship between sAA and performance. In a laboratory-controlled environment, we investigated the relationship between sAA levels, subjective sleepiness, and performance during two days (50h) of total sleep deprivation. Beginning at 09:00, twelve healthy participants (5 females) aged 22.5±2.5years (mean±SD) provided saliva s les, recorded ratings of subjective sleepiness, completed a brief 3-min psychomotor vigilance task (PVT-B) and performed a 40-min simulated driving task, at regular 3h intervals during wakefulness. Ratings of subjective sleepiness exhibited a constant linear increase (p<0.001) during sleep deprivation. In contrast, sAA levels showed a marked diurnal profile, with levels increasing during the day (p<0.001) and steadily declining in the evening and early-morning (p<0.001). PVT-B (mean reaction time and mean slowest 10% reaction time) and simulated driving performance (speed deviation and lane deviation) also exhibited diurnal profiles across the two days of sleep deprivation. Performance peaked in the afternoon (p<0.001) and then steadily worsened as wakefulness continued into the evening and early-morning (p<0.001). Further analysis revealed that higher sAA levels in the hour preceding each performance assessment were associated with better PVT-B and driving performance (p<0.001). These findings suggest that sAA measures may be suitable indicators of performance deficits during sustained wakefulness and highlight the potential for sAA to be considered for physiological monitoring of performance. In operational environments sAA levels, as part of a panel of physiological measures, may be useful for assessing fitness-for-duty prior to safety being compromised or when performance deficits are unknown.
Publisher: Elsevier BV
Date: 2011
DOI: 10.1016/J.APERGO.2010.06.009
Abstract: Research suggests that less than 5 h sleep in the 24 h prior to work and/or more than 16 h of wakefulness can significantly increase the likelihood of fatigue-related impairment and error at work. Studies have also shown exponential safety declines with time on shift, with roughly double the likelihood of accident or injury after 10 h relative to the first 8h. While it is acknowledged that reduced sleep, increased wakefulness and longer work hours produce work-related fatigue, few studies have examined the impact of workload on this relationship. Studies in the rail industry have focused on drivers. This study investigated fatigue in a large s le of Australian Rail Industry Employees. Participants were from four companies (n = 90: 85m, 5f mean age 40.2 ± 8.6 y). Data was analysed for a total of 713 shifts. Subjects wore wrist actigraphs and completed sleep and work diaries for 14-days. They also completed the Samn-Perelli Fatigue Scale at the beginning and end of shifts, and the NASA-TLX workload scale at least twice during each shift. Average (±SD) sleep length (7.2 ± 2.6h), prior wake at shift end (12.0 ± 4.7h), shift duration (8.0 ± 1.3) and fatigue (4.1 ± 1.3, "a little tired, less than fresh") were within limits generally considered acceptable from a fatigue perspective. However, participants received 5 h or less sleep in the prior 24 h on 13%, were awake for at least 16 h at the end of 16% and worked at least 10 h on 7% of shifts. Subjects reported that they felt "extremely tired, very difficult to concentrate," or "completely exhausted, unable to function effectively" on 13% of shifts. Sleep length (OR = 0.88, p < 0.01), shift duration (OR = 1.18, p < 0.05), night shift (REF = morning shift, OR = 2.12, p < 0.05) and workload ratings (OR = 1.2, p < 0.05) were significant predictors of ratings of extreme tiredness/exhaustion (yes/no). While on average, sleep loss, extended wakefulness, longer work hours and work-related fatigue do not appear problematic in this s le, there is still a notable percentage of shifts that are likely to be associated with high levels of work-related fatigue. Given the size of the Australian Rail Industry, with thousands of shifts occurring each day, this is potentially of operational concern. Further, results indicate that, in addition to sleep length, wakefulness and work hours, workload significantly influences fatigue. This has possible implications for bio-mathematical predictions of fatigue and for fatigue management more generally.
Publisher: Elsevier
Date: 2023
Publisher: American Thoracic Society
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 07-07-2010
Publisher: Elsevier BV
Date: 10-2018
DOI: 10.1016/J.SMRV.2018.03.004
Abstract: There is a wealth of evidence to say that sleep impacts maternal health during pregnancy, however, little has been published on fetal health and maternal sleep. This scoping review summarises current literature on maternal sleep including sleep disordered breathing, sleep quality, sleep duration and supine sleep position, as these relate to fetal outcomes specifically birth weight, growth, preterm birth and stillbirth. An overall interpretation of the studies evaluated shows that events occurring during maternal sleep such as obstructive sleep apnea, sleep disruption and sleep position may have a negative effect on the fetus resulting in altered growth, gestational length and even death. These effects are biologically and physically plausible. In conclusion, there is limited and often conflicting information on maternal sleep and fetal outcomes. However, existing evidence suggests that this is an important area for future research. This area is ripe for investigation if there is to be reduction in the physical, emotional, and financial burden of poor fetal outcomes related to maternal sleep.
Publisher: Springer Science and Business Media LLC
Date: 24-02-2020
Publisher: Research Square Platform LLC
Date: 10-09-2020
DOI: 10.21203/RS.3.RS-31807/V2
Abstract: Background: To describe demographic and clinical factors associated with the prevalence and incidence of depression and explore the temporal relationship between depression and joint symptoms in patients with symptomatic knee osteoarthritis (OA). Methods: 413 participants were selected from a randomized controlled trial in people with symptomatic knee OA and vitamin D deficiency (age 63.2 ± 7.0 year, 50.4% female). Depression severity and knee joint symptoms were assessed using the patient health questionnaire (PHQ-9) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), respectively, at baseline and 24 months. Results: The prevalence and incidence of depression was 25.4% and 11.2%, respectively. At baseline, having younger age, a higher body mass index (BMI), greater scores of WOMAC pain (PR: 1.05, 95%CI:1.03, 1.07), dysfunction (PR: 1.02, 95%CI:1.01, 1.02) and stiffness (PR: 1.05, 95%CI: 1.02, 1.09), lower education level, having more than one comorbidity and having two or more painful body sites were significantly associated with a higher prevalence of depression. Over 24 months, being female, having a higher WOMAC pain (RR: 1.05, 95%CI: 1.02, 1.09) and dysfunction score (RR: 1.02, 95%CI: 1.01, 1.03) at baseline and having two or more painful sites were significantly associated with a higher incidence of depression. In contrast, baseline depression was not associated with changes in knee joint symptoms over 24 months. Conclusion: Knee OA risk factors and joint symptoms, along with co-existing multi-site pain are associated with the prevalence and development of depression. This suggests that managing common OA risk factors and joint symptoms may be important for prevention and treatment depression in patients with knee OA. Trial registration: ClinicalTrials.gov identifier: NCT01176344Anzctr.org.au identifier: ACTRN12610000495022
Publisher: Research Square Platform LLC
Date: 03-11-2020
DOI: 10.21203/RS.3.RS-31807/V3
Abstract: Background: To describe demographic and clinical factors associated with the presence and incidence of depression and explore the temporal relationship between depression and joint symptoms in patients with symptomatic knee osteoarthritis (OA). Methods: 397 participants were selected from a randomized controlled trial in people with symptomatic knee OA and vitamin D deficiency (age 63.3 ± 7.1 year, 48.6% female). Depression severity and knee joint symptoms were assessed using the patient health questionnaire (PHQ-9) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), respectively, at baseline and 24 months. Results: The presence and incidence of depression was 25.4% and 11.2%, respectively. At baseline, having younger age, a higher body mass index (BMI), greater scores of WOMAC pain (PR: 1.05, 95%CI:1.03, 1.07), dysfunction (PR: 1.02, 95%CI:1.01, 1.02) and stiffness (PR: 1.05, 95%CI: 1.02, 1.09), lower education level, having more than one comorbidity and having two or more painful body sites were significantly associated with a higher presence of depression. Over 24 months, being female, having a higher WOMAC pain (RR: 1.05, 95%CI: 1.02, 1.09) and dysfunction score (RR: 1.02, 95%CI: 1.01, 1.03) at baseline and having two or more painful sites were significantly associated with a higher incidence of depression. In contrast, baseline depression was not associated with changes in knee joint symptoms over 24 months. Conclusion: Knee OA risk factors and joint symptoms, along with co-existing multi-site pain are associated with the presence and development of depression. This suggests that managing common OA risk factors and joint symptoms may be important for prevention and treatment depression in patients with knee OA. Trial registration: ClinicalTrials.gov identifier: NCT01176344Anzctr.org.au identifier: ACTRN12610000495022
Publisher: Research Square Platform LLC
Date: 31-05-2020
DOI: 10.21203/RS.3.RS-31807/V1
Abstract: Background To describe demographic and clinical factors associated with the prevalence and incidence of depression and explore the temporal relationship between depression and joint symptoms in patients with symptomatic knee osteoarthritis (OA). Methods 413 participants were selected from a randomized controlled trial in people with symptomatic knee OA and vitamin D deficiency (age 63.2 ± 7.0 year, 50.4% female). Depression severity and knee joint symptoms were assessed using the patient health questionnaire (PHQ-9) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), respectively, at baseline and 24 months. Results The prevalence and incidence of depression was 25.4% and 11.2%, respectively. At baseline, having a higher body mass index (BMI), greater scores of WOMAC pain (PR: 1.05, 95%CI:1.03, 1.07), dysfunction (PR: 1.02, 95%CI:1.01, 1.02) and stiffness (PR: 1.05, 95%CI: 1.02, 1.09), lower education level, having more than one comorbidity and having two or more painful body sites were significantly associated with a higher prevalence of depression. Over 24 months, being female, having a higher WOMAC pain (RR: 1.04, 95%CI: 1.00, 1.08) and dysfunction score (RR: 1.01, 95%CI: 1.00, 1.02) at baseline and having two or more painful sites were significantly associated with a higher incidence of depression. In contrast, baseline depression was not associated with changes in knee joint symptoms over 24 months. Conclusion Knee OA risk factors and joint symptoms, along with co-existing multi-site pain are associated with the prevalence and development of depression. This suggests that managing common OA risk factors and joint symptoms could be important for prevention and treatment depression in patients with knee OA.
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.SLEH.2022.02.004
Abstract: To examine whether the association previously reported between mobile phone use at night and poor sleep in adolescents also generalizes to pre-adolescent children. Cross sectional. Database provided by Resilient Youth Australia Pty Ltd. Survey completed by 84,915 pre-adolescent (8-11 years), 99,680 early adolescent (12-14 years) and 67,600 late adolescent Australian children (15-18 years). Children were asked how frequently they obtained 8 hours of sleep on most nights and if they used their mobile phone at night to send and receive messages between 10 PM and 6 AM. Binary logistic regression analyses were used to examine the association between mobile phone use at night and sleeping 8h or more on most nights with gender, socioeconomic status and year of study (2014-2018) as covariates. For all age cohorts including pre-adolescent children, mobile phone use at night was associated with lower odds of obtaining 8 hours of sleep on most nights. The present findings confirm that the association between mobile phone use at night and poor sleep previously reported in adolescent children also generalises to pre-adolescent children. Given the increased uptake of smartphone devices in ever younger children the findings point to the need to provide parents, schools and communities with resources to promote child sleep hygiene and media use at bedtime.
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.AAP.2015.11.010
Abstract: Night shift workers are at risk of road accidents due to sleepiness on the commute home. A brief nap at the end of the night shift, before the commute, may serve as a sleepiness countermeasure. However, there is potential for sleep inertia, i.e. transient impairment immediately after awakening from the nap. We investigated whether sleep inertia diminishes the effectiveness of napping as a sleepiness countermeasure before a simulated commute after a simulated night shift. N=21 healthy subjects (aged 21-35 y 12 females) participated in a 3-day laboratory study. After a baseline night, subjects were kept awake for 27h for a simulated night shift. They were randomised to either receive a 10-min nap ending at 04:00 plus a 10-min pre-drive nap ending at 07:10 (10-NAP) or total sleep deprivation (NO-NAP). A 40-min York highway driving task was performed at 07:15 to simulate the commute. A 3-min psychomotor vigilance test (PVT-B) and the Samn-Perelli Fatigue Scale (SP-Fatigue) were administered at 06:30 (pre-nap), 07:12 (post-nap), and 07:55 (post-drive). In the 10-NAP condition, total pre-drive nap sleep time was 9.1±1.2min (mean±SD), with 1.3±1.9min spent in slow wave sleep, as determined polysomnographically. There was no difference between conditions in PVT-B performance at 06:30 (before the nap). In the 10-NAP condition, PVT-B performance was worse after the nap (07:12) compared to before the nap (06:30) no change across time was found in the NO-NAP condition. There was no significant difference between conditions in PVT-B performance after the drive. SP-Fatigue and driving performance did not differ significantly between conditions. In conclusion, the pre-drive nap showed objective, but not subjective, evidence of sleep inertia immediately after awakening. The 10-min nap did not affect driving performance during the simulated commute home, and was not effective as a sleepiness countermeasure.
Publisher: Hindawi Limited
Date: 11-05-2011
DOI: 10.5402/2011/821514
Abstract: Nurses (, age = 39 ± 11 y) from an Australian metropolitan hospital completed the Marcus Alcoholism, Seaman Mannello Nurses' Attitudes toward Alcoholism, and the shortened Alcohol and Alcohol Problems Perception Questionnaires. The majority had personal (73%) and/or professional (93%) experience with people with alcohol problems. Not one reported receiving drug and alcohol training. On average, nurses held neutral to positive attitudes toward alcohol problems however, 14.3% completely disagreed with the statement “I want to work with drinkers,” and 12.5% completely disagreed that they were likely to find working with people with alcohol problems rewarding. Attitudes to care were significantly influenced by age, personal drinking habits, and beliefs about whether patients can be helped, whether alcoholism is a character defect, and the relationship between alcoholism and social status. Negative attitudes towards patient care persist and are influenced by age, personal drinking habits, and beliefs about alcoholism. Specific training in this area may be beneficial.
Publisher: Informa UK Limited
Date: 26-01-2018
DOI: 10.1080/07420528.2018.1430037
Abstract: Studies suggest that there may be an association between sleep and growth however, the relationship is not well understood. Changes in biology and external factors such as school schedule heavily impact the sleep of adolescents, during a critical phase for growth. This study assessed the changes in sleep across school days, weekends and school holidays, while also measuring height and weight changes, and self-reported alterations in food intake and physical activity. The impact of morningness-eveningness (M-E) on height change and weight gain was also investigated. In a s le of 63 adolescents (mean age = 13.13, SD = 0.33, 31 males) from two independent schools in South Australia, height and weight were measured weekly for 4 weeks prior to the school holidays and 4 weeks after the school holidays. Participants also completed a Morningness/Eveningness Scale and 7-day sleep, diet and physical activity diaries prior to, during and after the school holidays. Participants at one school had earlier wake times during the weekends than participants attending the other school, leading to a significantly shorter sleep duration on weekends for those participants. Regardless of school, sleep was significantly later and longer during the holidays (p < 0.001) and those with a stronger morning preference fell asleep (F
Publisher: Springer Science and Business Media LLC
Date: 11-09-2020
DOI: 10.1038/S41598-020-71800-6
Abstract: Higher and lower levels of alertness typically lead to a leftward and rightward bias in attention, respectively. This relationship between alertness and spatial attention potentially has major implications for health and safety. The current study examined alertness and spatial attention under simulated shiftworking conditions. Nineteen healthy right-handed participants (M = 24.6 ± 5.3 years, 11 males) completed a seven-day laboratory based simulated shiftwork study. Measures of alertness (Stanford Sleepiness Scale and Psychomotor Vigilance Task) and spatial attention (Landmark Task and Detection Task) were assessed across the protocol. Detection Task performance revealed slower reaction times and higher omissions of peripheral (compared to central) stimuli, with lowered alertness suggesting narrowed visuospatial attention and a slight left-sided neglect. There were no associations between alertness and spatial bias on the Landmark Task. Our findings provide tentative evidence for a slight neglect of the left side and a narrowing of attention with lowered alertness. The possibility that one’s ability to sufficiently react to information in the periphery and the left-side may be compromised under conditions of lowered alertness highlights the need for future research to better understand the relationship between spatial attention and alertness under shiftworking conditions.
Publisher: Research Square Platform LLC
Date: 18-12-2020
DOI: 10.21203/RS.3.RS-31807/V4
Abstract: Background: To describe demographic and clinical factors associated with the presence and incidence of depression and explore the temporal relationship between depression and joint symptoms in patients with symptomatic knee osteoarthritis (OA). Methods: 397 participants were selected from a randomized controlled trial in people with symptomatic knee OA and vitamin D deficiency (age 63.3 ± 7.1 year, 48.6% female). Depression severity and knee joint symptoms were assessed using the patient health questionnaire (PHQ-9) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), respectively, at baseline and 24 months. Results: The presence and incidence of depression was 25.4% and 11.2%, respectively. At baseline, having younger age, a higher body mass index (BMI), greater scores of WOMAC pain (PR: 1.05, 95%CI:1.03, 1.07), dysfunction (PR: 1.02, 95%CI:1.01, 1.02) and stiffness (PR: 1.05, 95%CI: 1.02, 1.09), lower education level, having more than one comorbidity and having two or more painful body sites were significantly associated with a higher presence of depression. Over 24 months, being female, having a higher WOMAC pain (RR: 1.05, 95%CI: 1.02, 1.09) and dysfunction score (RR: 1.02, 95%CI: 1.01, 1.03) at baseline and having two or more painful sites were significantly associated with a higher incidence of depression. In contrast, baseline depression was not associated with changes in knee joint symptoms over 24 months. Conclusion: Knee OA risk factors and joint symptoms, along with co-existing multi-site pain are associated with the presence and development of depression. This suggests that managing common OA risk factors and joint symptoms may be important for prevention and treatment depression in patients with knee OA. Trial registration: ClinicalTrials.gov identifier: NCT01176344Anzctr.org.au identifier: ACTRN12610000495022
Publisher: Elsevier BV
Date: 12-2006
DOI: 10.1016/J.JOCA.2006.05.010
Abstract: There is evidence for tibial bone area to increase in response to risk factors for knee osteoarthritis (OA) in healthy subjects and to increase over time in subjects with knee OA. We performed a cohort study to examine whether tibial plateau bone area changes over time in healthy subjects and identify factors influencing the change. Eighty-one healthy women (age range 50-76 years) underwent magnetic resonance imaging (MRI) on their dominant knee at baseline and approximately 2.5 years later. Tibial plateau bone area was measured at baseline and follow-up. Risk factors assessed at baseline were tested for their association with change in tibial plateau bone area over time using multiple linear regression. The mean tibial plateau bone area increased from 1733+/-209 to 1782+/-203 mm(2) for the medial, and from 1090+/-152 to 1109+/-152 mm(2) for the lateral over the study period, representing an annual average increase rate of 1.2% (95% CI 0.03%, 1.6%) and 0.8% (95% CI 0.7%, 1.8%), respectively. Baseline tibial plateau bone area was inversely associated with the increase rate of tibial plateau bone area. There was a trend for static knee alignment to be related to the increase rate of tibial plateau bone area. In healthy women, tibial plateau bone area increases over time. Baseline tibial plateau bone area is the main factor affecting the rate of increase, with biomechanical factors, such as static anatomical alignment, likely to affect the expansion of tibial plateau. Further work will be needed to determine the effect of subchondral bone change in the pathogenesis of knee OA.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.AAP.2018.01.007
Abstract: Technology-supported methods for sleep recording are becoming increasingly affordable. Sleep history feedback may help with fatigue-related decision making - Should I drive? Am I fit for work? This study examines a "sleep tank" model (SleepTank
Publisher: Elsevier BV
Date: 04-2006
DOI: 10.1016/J.JOCA.2005.11.006
Abstract: The influence exerted on cartilage and bone volumes by locomotor patterns is poorly understood, particularly at the patellofemoral joint. The aim of this study was to investigate the relationship between sagittal plane movement at the tibiofemoral joint and patella cartilage and bone volumes during the locomotion of healthy adult females. Three-dimensional Vicon gait analyses and magnetic resonance imaging were performed on 20 healthy adult women. The relationships between the degree of tibiofemoral flexion and extension at varying stages of the gait cycle and the concomitant medial, lateral and total patella cartilage and total bone volumes were examined. For every degree the knee flexed during mid-stance, there was a 62.8 microL (95% confidence interval 3.7-122.0) increase in the medial patella facet cartilage volume after adjustment for age and the body mass index (BMI) (P = 0.04). A similar relationship that approached significance was observed for the lateral patella facet cartilage volume after adjustment for age and the BMI (P = 0.08). No association was observed between the sagittal plane tibiofemoral movements and the patella bone volume. The association between patella cartilage volume and tibiofemoral knee movement suggests that for every degree increase in knee flexion during mid-stance, there is an associated increase in patella cartilage volume. This may be the result of the geometry of the femoral condyle influencing patella tracking and or the retropatellar load exerted on the patella during walking. These results may have important implications for people who hyperextend their knee during gait and the pathogenesis of patellofemoral osteoarthritis.
Publisher: Elsevier
Date: 2019
DOI: 10.1016/BS.PBR.2019.03.010
Abstract: An emerging literature is specifically focusing on the effects of sleep deprivation on aspects of social functioning and underlying neural changes. Two critical facets of social behavior emerge that are negatively impacted by sleep deprivation-self-regulation, which includes behavioral and emotional regulation, and social monitoring, which includes perceiving and interpreting cues relating to self and others. Sleep deprived in iduals performing tasks with social components show altered brain activity in areas of the prefrontal cortex implicated in self-control, inhibition, evaluation, and decision-making, in proximity to mesocorticolimbic pathways to reward and emotional processing areas. These cognitive changes lead to increased reward seeking and behaviors that promote negative health outcomes (such as increased consumption of indulgence foods). These changes also lead to emotional disinhibition and increased responses to negative stimuli, leading to reductions in trust, empathy, and humor. Concomitant attentional instability leads to impaired social information processing, impairing in idual and team performance and increasing likelihood of error, incident, and injury. Together, changes to reward seeking, the foundational components of social interaction, and interpretation of social cues, can result in unpleasant or deviant behavior. These behaviors are perceived and negatively responded to by others, leading to a cycle of conflict and withdrawal. Further studies are necessary and timely. Educational and behavioral interventions are required to reduce health-damaging behaviors, and to reduce emotionally-laden negative interpretation of sleep-deprived exchanges. This may assist with health, and with team cohesion (and improved performance and safety) in the workplace and the home.
Publisher: Oxford University Press (OUP)
Date: 03-2016
DOI: 10.5665/SLEEP.5550
Publisher: BMJ
Date: 03-2004
Abstract: No consistent relationship between the severity of symptoms of knee osteoarthritis (OA) and radiographic change has been demonstrated. To determine the relationship between symptoms of knee OA and tibial cartilage volume, whether pain predicts loss of cartilage in knee OA, and whether change in cartilage volume over time relates to change in symptoms over the same period. 132 subjects with symptomatic, early (mild to moderate) knee OA were studied. At baseline and 2 years later, participants had MRI scans of their knee and completed questionnaires quantifying symptoms of knee OA (knee-specific WOMAC: pain, stiffness, function) and general physical and mental health (SF-36). Tibial cartilage volume was determined from the MRI images. Complete data were available for 117 (89%) subjects. A weak association was found between tibial cartilage volume and symptoms at baseline. The severity of the symptoms of knee OA at baseline did not predict subsequent tibial cartilage loss. However, weak associations were seen between worsening of symptoms of OA and increased cartilage loss: pain (r(s) = 0.28, p = 0.002), stiffness (r(s) = 0.17, p = 0.07), and deterioration in function (r(s) = 0.21, p = 0.02). Tibial cartilage volume is weakly associated with symptoms in knee OA. There is a weak association between loss of tibial cartilage and worsening of symptoms. This suggests that although cartilage is not a major determinant of symptoms in knee OA, it does relate to symptoms.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.SMRV.2019.101216
Abstract: In 24/7 operations, fatigue from extended work hours and shift work is ubiquitous. Fatigue is a significant threat to performance, productivity, safety, and well-being, and strategies for managing fatigue are an important area of research. At the level of in iduals, the effects of fatigue on performance are relatively well understood, and countermeasures are widely available. At the level of organizations, the effects of fatigue are also relatively well understood, and organizational approaches to fatigue risk management are increasingly well documented. However, in most organizational settings, in iduals work in teams, and teams are the building blocks of the organizational enterprise. Yet, little is known about the effects of fatigue on team functioning. Here we discuss the effects of fatigue at the levels of in iduals, teams, and organizations, and how the consequences of fatigue cross these levels to impact overall productivity and safety. Furthermore, we describe the pivotal role of teams in understanding the adverse organizational effects of fatigue in 24/7 operations and argue that teams may be leveraged to mitigate these effects. Systematic investigation of the effects of fatigue on teams is a promising avenue toward advances in fatigue risk management and provide some ideas for how this may be approached.
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.EXGER.2022.111698
Abstract: The relationships between cognitive function and each of physical activity, sleep and sedentary behaviour in older adults are well documented. However, these three "time use" behaviours are co-dependent parts of the 24-hour day (spending time in one leaves less time for the others), and their best balance for cognitive function in older adults is still largely unknown. This systematic review summarises the existing evidence on the associations between combinations of two or more time-use behaviours and cognitive function in older adults. Embase, Pubmed, PsycInfo, Medline and Emcare databases were searched in March 2020 and updated in May 2021, returning a total of 25,289 papers for screening. A total of 23 studies were included in the synthesis, spanning >23,000 participants (mean age 71 years). Findings support previous evidence that spending more time in physical activity and limiting sedentary behaviour is broadly associated with better cognitive outcomes in older adults. Higher proportions of moderate-vigorous physical activity in the day were most frequently associated with better cognitive function. Some evidence suggests that certain types of sedentary behaviour may be positively associated with cognitive function, such as reading or computer use. Sleep duration appears to share an inverted U-shaped relationship with cognition, as too much or too little sleep is negatively associated with cognitive function. This review highlights considerable heterogeneity in methodological and statistical approaches, and encourages a more standardised, transparent approach to capturing important daily behaviours in older adults. Investigating all three time-use behaviours together against cognitive function using suitable statistical methodology is strongly recommended to further our understanding of optimal 24-hour time use for brain function in aging.
Publisher: Public Library of Science (PLoS)
Date: 23-07-2012
Publisher: Springer Science and Business Media LLC
Date: 23-08-2010
Publisher: Elsevier
Date: 2014
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.AAP.2015.11.011
Abstract: It has been suggested that shiftworkers may consume alcohol to help them sleep, resulting in greater consumption. A large study in Australian workers suggested that those on non-standard schedules (outside 8am-6pm, Monday-Friday) do not drink more, but are at increased odds of binge drinking (heavy periods of drinking followed by abstinence) than workers on standard schedules. However, differences in types of non-standard schedules were not examined in the study. The current study examined the alcohol intake of Australian shiftworkers on fixed and rotating shifts. Shiftworkers (n=118, age=43.4±9.9y, 68% male) on 12h-rotating (n=29), 8h-rotating (n=29), morning (n=33) and night (n=27) schedules from printing, postal, nursing and oil industries participated. They completed a Cancer Council Dietary Questionnaire, recording frequency and amount of alcohol consumed on average per day over the preceding year. They also completed a shortened Standard Shiftwork Index, including questions on shift schedule, sleep duration, tiredness, gender and age. Average alcohol consumption was 9.6±13.1 standard drinks/week. One in six reported using alcohol as a sleep aid between shifts at least sometimes and nearly one third reported consuming 12 or more drinks in 24h. Alcohol consumption was higher for males and decreased with age. Controlling for gender and age, there were no significant differences between shift types in standard drinks/week (p=0.50). However, those on 12-h rotating shifts consumed more drinks per 24h (p=0.04) and had less sleep (p<0.001). Results support the suggestion that shiftworkers are likely to binge drink, particularly younger, male workers and those on long, rotating shifts. Alcohol use in shiftworkers may put increased pressure on already vulnerable physiological systems.
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.AAP.2015.11.012
Abstract: There is evidence that a decrease in alertness is associated with a rightward shift of attention. Alertness fluctuates throughout the day and peak times differ between in iduals. Some in iduals feel most alert in the morning others in the evening. Our aim was to investigate the influence of morningness/eveningness and time of testing on spatial attention. It was predicted that attention would shift rightwards when in iduals were tested at their non-optimal time as compared to tests at peak times. A crowdsourcing internet marketplace, Amazon Mechanical Turk (AMT) was used to collect data. Given questions surrounding the quality of data drawn from such virtual environments, this study also investigated the sensitivity of data to demonstrate known effects from the literature. Five-hundred and thirty right-handed participants took part between 6 am and 11 pm. Participants answered demographic questions, completed a question from the Horne and Östberg Morningness/Eveningness Scale, and performed a spatial attentional task (landmark task). For the landmark task, participants indicated whether the left or right segment of each of 72 pre-bisected lines was longer (longer side counterbalanced). Response bias was calculated by subtracting the 'number of left responses' from the 'number of right responses', and iding by the number of trials. Negative values indicate a leftward attentional bias, and positive values a rightward bias. Well-supported relationships between variables were reflected in the dataset. Controlling for age, there was a significant interaction between morningness/eveningness and time of testing (morning=6 am-2.30 pm, evening=2.30 pm-11 pm) (p<0.05) such that there was a relative rightward shift of attention from peak to off-peak times of testing for those identifying as morning types, but not evening types. Findings support the utility of crowdsourcing internet marketplaces as data collection vehicles for research. Results also suggest that the deployment of spatial attention is modulated by an in idual's peak time (morningness/eveningness) and time of testing.
Publisher: Springer Science and Business Media LLC
Date: 11-2008
Publisher: Informa UK Limited
Date: 2006
DOI: 10.1080/07420520601083391
Abstract: Fatigue is an increasingly noted factor in road accidents. The ability to predict and be aware of impairment in terms of driving capability is important for potential legal liability and road safety. However, to date, there have been few studies that have investigated the accuracy of in iduals in predicting how safely they could drive during conditions of sleep loss. Research has demonstrated that in iduals rate themselves as better than the population average in a number of domains, including driving-related skills. Therefore, this study also aimed to investigate self-ratings of predicted driving ability during extended wakefulness and compare them to ratings made of a hypothetical other person under the same conditions. Thirty-two participants remained awake for a period of 40 h. Every 2 h, they completed the Psychomotor Vigilance Task (PVT) and rated on a seven-point scale how well they thought they could drive safely, react quickly in an emergency, and stay in their own lane. They were also asked to assess how they thought someone else in their own position could drive. The participants rated their driving ability as becoming significantly poorer at the same time that their PVT performance became significantly slower. Self-ratings indicating a qualitative assessment of poorer than neutral driving occurred at 03:00 h for both the "drive safely" and "react quickly" questions, after 19 h of continuous wakefulness (starting at 08:00 h). This occurred at 05:00 h for the "keep in my lane" question. Previous studies with a similar protocol demonstrated that under these conditions, in iduals exhibit a performance decrements equivalent to someone with a blood alcohol concentration of 0.05% (the legal driving limit in Australia). Participants consistently rated the ability of others to drive as poorer than their own. The main implication from this study for road safety and legal liability is that it is reasonable to focus on a person's perception of the situation, as it does align with objective reality to a certain extent. A concern in terms of road safety is potential overconfidence, indicated by rating others consistently poorer than themselves.
Publisher: Humana Press
Date: 2007
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2007
DOI: 10.1097/GME.0B013E31802F316B
Abstract: Exercise has been strongly promoted for the prevention of the major diseases of aging in women, such as cardiovascular disease and osteoporosis. However, conflicting data exist as to whether exercise benefits joint health and thus helps protect against degenerative processes such as knee osteoarthritis. The aim of this study was to examine the cross-sectional relationship between exercise and knee joint cartilage in women at midlife. A total of 176 women aged 40 to 67 years with no clinical knee osteoarthritis or history of significant knee injury were recruited from the community and had magnetic resonance imaging performed on their dominant knee to assess tibial cartilage volume and defects. The women completed a questionnaire to determine fortnightly exercise participation and frequency. Fortnightly participation in exercise at an intensity that caused tachypnea and an increased pulse rate for at least 20 minutes was positively associated with the volume of the medial tibial cartilage (P=0.02). There was a tendency for the frequency of exercise at this intensity to be positively associated with medial tibial cartilage volume (P=0.07). Exercise participation was not significantly associated with the presence of knee cartilage defects. Participation in exercise that causes tachypnea and an increased pulse rate for at least 20 minutes was associated with greater medial tibial cartilage volume, but not knee cartilage defects in non-healthcare-seeking women at midlife. More frequent exercise also tended to be associated with greater medial tibial cartilage volume. Although our findings need to be confirmed longitudinally, they provide further support for a beneficial effect of regular exercise on diseases related to aging.
Publisher: National Institute of Industrial Health
Date: 2014
Publisher: Informa UK Limited
Date: 13-10-2016
DOI: 10.1080/07420528.2016.1237520
Abstract: Shiftworkers have impaired performance when driving at night and they also alter their eating patterns during nightshifts. However, it is unknown whether driving at night is influenced by the timing of eating. This study aims to explore the effects of timing of eating on simulated driving performance across four simulated nightshifts. Healthy, non-shiftworking males aged 18-35 years (n = 10) were allocated to either an eating at night (n = 5) or no eating at night (n = 5) condition. During the simulated nightshifts at 1730, 2030 and 0300 h, participants performed a 40-min driving simulation, 3-min Psychomotor Vigilance Task (PVT-B), and recorded their ratings of sleepiness on a subjective scale. Participants had a 6-h sleep opportunity during the day (1000-1600 h). Total 24-h food intake was consistent across groups however, those in the eating at night condition ate a large meal (30% of 24-h intake) during the nightshift at 0130 h. It was found that participants in both conditions experienced increased sleepiness and PVT-B impairments at 0300 h compared to 1730 and 2030 h (p < 0.001). Further, at 0300 h, those in the eating condition displayed a significant decrease in time spent in the safe zone (p < 0.05 percentage of time within 10 km/h of the speed limit and 0.8 m of the centre of the lane) and significant increases in speed variability (p < 0.001), subjective sleepiness (p < 0.01) and number of crashes (p < 0.01) compared to those in the no eating condition. Results suggest that, for optimal performance, shiftworkers should consider restricting food intake during the night.
Publisher: Research Square Platform LLC
Date: 31-03-2022
DOI: 10.21203/RS.3.RS-1497205/V1
Abstract: Background: While targeting obesity is central to osteoarthritis management, recent meta-analyses demonstrate that significant weight loss has only modest effects on symptoms, and no effect on structure. In countries such as USA, adults gain on average 0.5 to 1 kilogram per year from early to middle adulthood. Preventing weight gain is easier to achieve and sustain than weight loss and reduces knee pain. The World Health Organisation has recommended that effective management of obesity should include prevention of weight gain, weight maintenance as well as weight loss however, it is unclear whether such recommendations appear in guidelines for osteoarthritis. Therefore, we systematically reviewed the recommendations and approaches for weight management in all current clinical practice guidelines (CPGs) for osteoarthritis. Methods: Nine databases were searched (1st January 2010 to 15th March 2022) to identify guidelines informing the non-pharmacological management of osteoarthritis. Three reviewers appraised guidelines according to the AGREE II instrument, and independently extracted data on their characteristics. One author extracted and summarised guideline recommendations on weight management. This systematic review is registered on PROSPERO (CRD42021274195). Results: Fifteen CPGs from developed and developing countries were included. Weight loss was recommended for knee (12 of 13 guidelines) and hip (10 of 11 guidelines) but not hand (0 of 4 guidelines) osteoarthritis. Combination approaches of diet and/or exercise were recommended for overweight or obese in iduals in knee (8 of 12) and hip (4 of 10) osteoarthritis, with 2 guidelines specifying ≥5% weight loss. One of 15 guidelines specified strategies for weight loss and maintenance of lost weight. Two of 15 guidelines recommended controlling body weight for osteoarthritis, regardless of obesity status. There was discordance between strength of recommendation for weight loss and level of evidence in 3 of 15 guidelines. The included guidelines had a median AGREE II domain score of 78.7% (interquartile range 71.4, 87.9). Conclusion: Most CPGs for knee and hip osteoarthritis recommend weight loss to manage obesity in osteoarthritis despite evidence for modest benefit. Given weight gain is common in adults, other approaches such as preventing weight gain should be considered to improve outcomes in osteoarthritis.
Publisher: MDPI AG
Date: 18-01-2022
DOI: 10.3390/NU14030420
Abstract: Cardiovascular disease (CVD) poses a serious health and economic burden worldwide. Modifiable lifestyle factors are a focus of research into reducing the burden of CVD, with diet as one of the most investigated factors. Specifically, the timing and regularity of food intake is an emerging research area, with approaches such as time-restricted eating (TRE) receiving much attention. TRE involves shortening the time available to eat across the day and is associated with improved CVD outcomes compared with longer eating windows. However, studies that have examined TRE have not considered the impact of sleep on CVD outcomes despite recent evidence showing that sleep duration can influence the timing and amount of food eaten. In this article, we argue that as TRE and sleep influence each other, and influence the same cardiometabolic parameters, experiencing inadequate sleep may attenuate any positive impact TRE has on CVD. We examine the relationship between TRE and CVD, with sleep as a potential mediator in this relationship, and propose a research agenda to investigate this relationship. This will provide necessary evidence to inform future interventions aimed at reducing the burden of CVD.
Publisher: Elsevier
Date: 2015
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.APERGO.2018.12.018
Abstract: The effects on dehydration and cognitive performance from heat and/or physical activity are well established in the laboratory, although have not yet been studied for personnel working in occupations such as wildland firefighting regularly exposed to these types of conditions. This study aimed to investigate the effects of temperature and dehydration on seventy-three volunteer firefighters (35.7 ± 13.7 years, mean ± standard deviation) during a simulation of wildfire suppression under either control or hot (18-20 or 33-35 °C) temperature conditions. Results showed cognitive performance on the psychomotor vigilance task declined when participants were dehydrated in the heat and Stroop task performance was impaired when dehydrated late in the afternoon. Firefighters may be at risk of deteriorations in simple cognitive functions in the heat whilst dehydrated, although may also experience impairments in complex cognitive functions if dehydrated late in the day, irrespective of the environmental temperature.
Publisher: Elsevier BV
Date: 10-2007
DOI: 10.1016/J.JOCA.2007.03.010
Abstract: Although the geometry of the trochlear groove is considered important in the pathogenesis of patellofemoral joint pathology it is unclear how the shape of the trochlear groove relates to patella morphology. This cross-sectional study investigated the relationship between the shape of the trochlear groove and patella cartilage and bone morphology in healthy adults. Two hundred and ninety-seven healthy adults aged between 50 and 79 years with no clinical history of knee pain or pathology were examined using magnetic resonance imaging (MRI). From the magnetic resonance (MR) images, the bony angles formed at the distal and proximal trochlear groove were measured, together with patella cartilage and bone volumes and patella cartilage defects. After adjustment for potential confounders, there was an 8.70mm(3) (95% confidence interval (CI) 2.15, 15.26) increase in patella cartilage volume (P=0.009), with no increased prevalence of cartilage defects (odds ratio=0.99 (95% CI 0.96, 1.02), P=0.35), for every 1 degrees increase (i.e., as the angle became more flatter) at the distal trochlear groove. Moreover, there was a 53.86mm(3) (95% CI -90.26, -17.46) reduction in patella bone volume for every 1 degrees that the angle at the distal trochlear groove became more flattened (P=0.004). No significant association between the proximal trochlear groove angle and the patella cartilage or bone properties was observed. A more flattened bony angle at the distal trochlear groove was associated with increased patella cartilage volume and reduced patella bone volume, but no increased prevalence of patella cartilage defects in adults with no history of knee pain or clinical disease. These cross-sectional findings suggest that a flattened distal trochlear groove may protect against degenerative patellofemoral conditions, such as osteoarthritis, but this will need to be confirmed in a longitudinal study.
Publisher: SAGE Publications
Date: 13-10-2013
Abstract: Midwives often work night and rotating shift schedules, which can lead to sleep disturbances, increased fatigue, and greater likelihood of accidents or errors. This study investigated the sleep of midwives ( n = 17) in an Australian metropolitan hospital. Midwives completed work and sleep logbooks and wore wrist actigraphs for 28 days. Midwives worked combinations of morning, afternoon, and/or night shifts on constant ( n = 6) or rotating schedules ( n = 11). They obtained less than recommended amounts of sleep, getting only 6–7 hr per 24-hr period. Morning shifts were associated with the lowest sleep durations, lowest subjective sleep quality, and highest postsleep fatigue ratings. Despite the significantly higher amount of wake after sleep onset (51 min), the sleep before afternoon shifts had significantly lower postsleep fatigue ratings and was rated as significantly higher quality than sleep before other shifts or days off. Those who were married or living with a partner reported significantly more sleep and lower postsleep fatigue than those who were separated or orced ( p .05). Seventy-one percent of midwives took naps, primarily before night shifts, with nearly 40% of nightshifts preceded by a nap. Average nap durations were nearly 1.5 hr. Midwives reported feeling moderately to very physically or mentally exhausted on 22–50% of all shifts and days off. Exhaustion was most common on night shift. This study suggests that midwives may be suffering from chronic sleep loss and as a consequence may be at risk of impairments in functioning that accompany fatigue.
Publisher: Elsevier BV
Date: 06-2000
DOI: 10.1016/S0378-5122(00)00118-3
Abstract: The menopause coincides with the appearance of many of the common arthritic conditions and with the lessening of severity of others such as SLE. The hormonal changes that occur may modulate these diseases. Thus, hormonal manipulation may have either beneficial or detrimental effects on the incidence and activity of a number of common joint diseases. We review the evidence regarding the effect of the menopause and oestrogen replacement therapy on the pathogenesis, incidence and prevalence and disease activity of osteoarthritis, rheumatoid arthritis, systemic lupus erythematosus and carpal tunnel syndrome.
Publisher: National Institute of Industrial Health
Date: 2010
DOI: 10.2486/INDHEALTH.MSSW-01
Abstract: Investigations of mood and workload in health care settings have focussed primarily on nurses and junior doctors. Given the critical shortfall in the Australian midwifery workforce, and the specialised nature of midwifery as an occupation, it is important to understand how mood and workload are experienced by midwives. Twenty midwives (18F, 2M) in an Australian metropolitan hospital completed logbooks assessing daily fluctuations in subjective mood and workload. Participants also provided information about history of psychopathology and sleep quality. Results revealed that midwives were relatively stable in terms of mood but did experience increased fear and decreased happiness when at work. Further, workload factors significantly predicted mood at work. Specifically, when participants felt that their work was more demanding and frustrating and required more effort, or when they felt that they could not accomplish all that was expected, mood was negatively influenced. This supports the connection between workload and negative mood change in healthcare. Given the potential for mood to influence a multitude of functions relevant to safety, performance and psychosocial wellbeing it is important to understand the factors which influence mood, particularly in light of the current shortfall in the Australian healthcare workforce.
Publisher: Wiley
Date: 2004
DOI: 10.1002/ART.11483
Abstract: Despite the increasing interest in knee cartilage volume as an outcome measure in studies of osteoarthritis (OA), it is unclear what components of knee cartilage will be most useful as markers of structural change in the tibiofemoral joint. This study was undertaken to longitudinally compare changes in femoral and tibial cartilage volume in patients with OA. One hundred seventeen patients with knee OA (58.1% women mean +/- SD age 63.7 +/- 10.2 years) were examined. Femoral and tibial cartilage volumes (medial and lateral tibiofemoral joints) were determined from T1-weighted fat-saturated magnetic resonance images of the knee from coronal views. The study population was followed up for a mean +/- SD of 1.9 +/- 0.2 years. In the medial tibiofemoral joint, the mean +/- SD loss of cartilage was 0.15 +/- 0.30 ml/year for femoral cartilage and 0.10 +/- 0.25 ml/year for tibial cartilage. In the lateral tibiofemoral joint, the average loss was 0.15 +/- 0.22 and 0.12 +/- 0.16 ml/year for femoral and tibial cartilage, respectively. There was a significant correlation between the degree of loss of tibial cartilage and the degree of loss of femoral cartilage, in both tibiofemoral joints (r = 0.81, P < 0.001 at the medial tibiofemoral joint r = 0.71, P < 0.001 at the lateral tibiofemoral joint). Longitudinal changes in tibial cartilage and those in femoral cartilage are strongly related to one another. This suggests that in tibiofemoral disease, measuring tibial cartilage alone may be adequate, given the facts that measurements of the total femoral cartilage are less reproducible and there are difficulties inherent in identifying the most appropriate component of femoral cartilage to measure.
Publisher: Wiley
Date: 23-04-2001
Publisher: Springer Science and Business Media LLC
Date: 16-10-2009
Publisher: MDPI
Date: 13-03-2018
Publisher: Oxford University Press (OUP)
Date: 23-03-2004
Publisher: Informa UK Limited
Date: 10-10-2019
DOI: 10.1080/07420528.2019.1676256
Abstract: Altering meal timing could improve cognition, alertness, and thus safety during the nightshift. This study investigated the differential impact of consuming a meal, snack, or not eating during the nightshift on cognitive performance (ANZCTR12615001107516). 39 healthy participants (59% male, age mean±SD: 24.5 ± 5.0y) completed a 7-day laboratory study and underwent four simulated nightshifts. Participants were randomly allocated to: Meal at Night (MN
Publisher: Springer Science and Business Media LLC
Date: 2006
DOI: 10.1186/AR1962
Publisher: National Institute of Industrial Health
Date: 2019
Publisher: Wiley
Date: 28-02-2003
DOI: 10.1002/ART.10840
Abstract: To compare tibial cartilage volume as measured by magnetic resonance imaging (MRI) with radiologic assessment of the tibiofemoral joint. The MRI-determined tibial cartilage volume was compared with the radiologic grade of in idual features of osteoarthritis (osteophytes and joint space narrowing [JSN]) in 252 subjects (mean +/- SD age 60.2 +/- 10 years, 62% female) who were participating in studies of knee cartilage. JSN seen on both medial and lateral radiographs of the tibiofemoral joint was inversely associated with the respective tibial cartilage volume. This inverse relationship was strengthened with adjustment for age, sex, body mass index (BMI), and bone size. After adjustment for these confounders, for every increase in JSN grade (0-3), the medial tibial cartilage volume was reduced by 257 mm(3) (95% confidence interval [95% CI] 193-321) and the lateral tibial cartilage volume by 396 mm(3) (95% CI 283-509). The relationship between mean cartilage volume and radiologic grade of JSN was linear. Based on results in the subgroup of subjects with normal radiographic findings, we have proposed a model to estimate average "normal" cartilage volume in men and women for a given age, BMI, and bone size. The results of this study demonstrate a strong negative, linear association between medial and lateral tibial cartilage volume and increasing grade of JSN. Using data from radiographically normal subjects, we have proposed a simple model for estimating "normal" cartilage volume. However, larger studies will be needed to confirm these findings and to determine whether they are valid in younger subjects.
Publisher: Oxford University Press (OUP)
Date: 19-07-2005
DOI: 10.1093/RHEUMATOLOGY/KEI018
Abstract: To determine whether articular cartilage defects are associated with cartilage loss and joint replacement in subjects with symptomatic knee osteoarthritis (OA). One hundred and seventeen subjects with symptomatic knee OA underwent magnetic resonance imaging of their dominant knee at baseline and 2 yr later. Cartilage defects were identified as prevalent (defect score > or =2) in each knee compartment. Occurrence of joint replacement by 4 yr was documented. Cartilage defects were present in 81% of medial, 64% of lateral tibiofemoral compartments and 55% of patellar cartilages. Annual patellar cartilage loss was highest in those with defects compared with no defects (5.5% vs 3.2%, P = 0.01). Tibial cartilage loss was not associated with defects in the medial (4.6% vs 5.8%, P = 0.42) or lateral (4.7% vs 6.5%, P = 0.21) tibial cartilages. Higher total cartilage defect scores (8-15) were associated with a 6.0-fold increased risk of joint replacement over 4 yr compared with those with lower scores (2-7) (95% confidence interval 1.6, 22.3), independently of potential confounders. Articular cartilage defects are associated with disease severity in knee OA and predict patellar cartilage loss and knee replacement.
Publisher: American Academy of Sleep Medicine (AASM)
Date: 15-06-2014
DOI: 10.5664/JCSM.3792
Publisher: Springer Science and Business Media LLC
Date: 2005
DOI: 10.1186/AR1726
Publisher: Springer Science and Business Media LLC
Date: 12-05-2021
DOI: 10.1038/S41598-021-89054-1
Abstract: Current evidence suggests that the ability to detect and react to information under lowered alertness conditions might be more impaired on the left than the right side of space. This evidence derives mainly from right-handers being assessed in computer and paper-and-pencil spatial attention tasks. However, there are suggestions that left-handers might show impairments on the opposite (right) side compared to right-handers with lowered alertness, and it is unclear whether the impairments observed in the computer tasks have any real-world implications for activities such as driving. The current study investigated the alertness and spatial attention relationship under simulated monotonous driving in left- and right-handers. Twenty left-handed and 22 right-handed participants (15 males, mean age = 23.6 years, SD = 5.0 years) were assessed on a simulated driving task (lasting approximately 60 min) to induce a time-on-task effect. The driving task involved responding to stimuli appearing at six different horizontal locations on the screen, whilst driving in a 50 km/h zone. Decreases in alertness and driving performance were evident with time-on-task in both handedness groups. We found handedness impacts reacting to lateral stimuli differently with time-on-task: right-handers reacted slower to the leftmost stimuli, while left-handers showed the opposite pattern (although not statistically significant) in the second compared to first half of the drive. Our findings support suggestions that handedness modulates the spatial attention and alertness interactions. The interactions were observed in a simulated driving task which calls for further research to understand the safety implications of these interactions for activities such as driving.
Publisher: SAGE Publications
Date: 09-2003
Abstract: In recent years, changes in the workplace have lead to increases in the incidence of fatigue and fatigue-related injuries. At the same time, there has been an increase in the scientific understanding of fatigue. The present article discusses the primary statutory instruments that regulate duties in the workplace to manage fatigue: Occupational Health and Safety legislation and regulations applicable to the road transport and aviation industries. Following this, the manner in which the criminal law and civil law address fatigue is also considered. In addition, other statutes exist that do not directly address fatigue management duties but must be considered when fatigue is addressed in the workplace. Workers Compensation legislation is discussed in this regard. It is argued that as they stand, the laws that seek to regulate fatigue are inconsistent with each other and with current scientific understanding. Suggestions are presented to address these shortcomings, and a proposal is made to create an offence of fatigued driving.
Publisher: Informa UK Limited
Date: 09-09-2019
DOI: 10.1080/07420528.2019.1660358
Abstract: Understanding shift workers dietary intake patterns may inform interventions targeted at lowering chronic disease risk. This study examined the temporal distribution of food intake as shift workers rotate between night shifts, day shift and/or days off to identify differences in energy intake, eating frequency, and adherence to dietary guidelines by shift type (night shift vs. day). Night shift (NS) workers completed a four-day food diary that included a minimum of two night shifts and one-day shift (DS)/day off (DO), recording all food, beverages and time of consumption. Comparisons were between shift types, using ANOVA for continuous data and generalized estimating equations for count data, data reported as mean (SE). When comparing NS and DSDO, there were no differences in energy intake (24 h) (8853 (702) vs. 9041 (605) kJ, n = 22) or adherence to dietary guidelines. There was no difference between the number of eating occasions on NS and DSDO (5.6(0.3) vs 5.1(0.6) occasions) but less energy per eating occasion at night (1661(125) vs 1933(159) kJ). When working NS compared with DSDO there was higher total sugar (%E, 19.1(2.0) vs 15.0(2.4)) and lower saturated fat (%E, 13.8(1.2) vs 15.7(1.3)). Further, DSDO were characterized by a pattern of three main meals and a prolonged fasting period. It is important to determine if reducing eating occasions and providing opportunities for fasting improves metabolic health.
Publisher: BMJ
Date: 2005
Publisher: OMICS Publishing Group
Date: 04-2007
Publisher: MDPI AG
Date: 15-06-2019
DOI: 10.3390/NU11061352
Abstract: Shiftworkers report eating during the night when the body is primed to sleep. This study investigated the impact of altering food timing on subjective responses. Healthy participants (n = 44, 26 male, age Mean ± SD = 25.0 ± 2.9 years, BMI = 23.82 ± 2.59kg/m2) participated in a 7-day simulated shiftwork protocol. Participants were randomly allocated to one of three eating conditions. At 00:30, participants consumed a meal comprising 30% of 24 h energy intake (Meal condition n = 14, 8 males), a snack comprising 10% of 24 h energy intake (Snack condition n = 14 8 males) or did not eat during the night (No Eating condition n = 16, 10 males). Total 24 h in idual energy intake and macronutrient content was constant across conditions. During the night, participants reported hunger, gut reaction, and sleepiness levels at 21:00, 23:30, 2:30, and 5:00. Mixed model analyses revealed that the snack condition reported significantly more hunger than the meal group (p 0.001) with the no eating at night group reporting the greatest hunger (p 0.001). There was no difference in desire to eat between meal and snack groups. Participants reported less sleepiness after the snack compared to after the meal (p 0.001) or when not eating during the night (p 0.001). Gastric upset did not differ between conditions. A snack during the nightshift could alleviate hunger during the nightshift without causing fullness or increased sleepiness.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.SLEEP.2016.12.016
Abstract: Napping is a widely used countermeasure to sleepiness and impaired performance caused by sleep loss and circadian pressure. Sleep inertia, the period of grogginess and impaired performance experienced after waking, is a potential side effect of napping. Many industry publications recommend naps of 30 min or less to avoid this side effect. However, the evidence to support this advice is yet to be thoroughly reviewed. Electronic databases were searched, and defined criteria were applied to select articles for review. The review covers literature on naps of 30 min or less regarding (a) sleep inertia, (b) slow-wave sleep (SWS) and (c) the relationship between sleep inertia and SWS. The review found that although the literature on short afternoon naps is relatively comprehensive, there are very few studies on naps of 30 min or less at night. Studies have mixed results regarding the onset of SWS and the duration and severity of sleep inertia following short naps, making guidelines regarding their use unclear. The varying results are likely due to differing sleep/wake profiles before the nap of interest and the time of the day at waking. The review highlights the need to have more detailed guidelines about the implementation of short naps according to the time of the day and prior sleep/wake history. Without this context, such a recommendation is potentially misleading. Further research is required to better understand the interactions between these factors, especially at night, and to provide more specific recommendations.
Publisher: Research Square Platform LLC
Date: 13-11-2019
Abstract: Background: Knee osteoarthritis (OA) is a common and important cause of pain and disability, but interventions aimed at modifying structures visible on imaging have been disappointing. While OA affects the whole joint, synovitis and effusion have been recognised as having a role in the pathogenesis of OA. Krill oil reduces knee pain and systemic inflammation and could be used for targeting inflammatory mechanisms of OA. Methods: 260 patients with clinical knee OA, significant knee pain and effusion-synovitis present on MRI will be recruited in 5 Australian cities (Hobart, Melbourne, Sydney, Adelaide and Perth). They will be randomly allocated to the two arms of the study, receiving 2g/day krill oil or inert placebo daily for 6 months. MRI of the study knee will be performed at screening, and after 6 months. Knee symptoms, function and MRI structural abnormalities will be assessed using validated methods. Safety data will be recorded. Primary outcomes are absolute change in knee pain (assessed by visual analog score) and change in size of knee effusion-synovitis over 24 weeks. Secondary outcomes include improvement in knee pain over 4, 8, 12, 16 and 20 weeks. The primary analyses will be intention-to-treat analyses of primary and secondary outcomes. Per protocol analyses adjusting for missing data and for treatment compliance will be performed as the secondary analyses. Discussion: This study will provide high-quality evidence to assess whether krill oil 2g/day reduces pain and effusion-synovitis size in older adults with clinical knee OA and knee effusion-synovitis. If krill oil is effective and confirmed to be safe, we will provide compelling evidence that krill oil improves pain and function, changes disease trajectory and slows disease progression in OA. Given the lack of approved therapies for slowing disease progression in OA, and moderate cost of krill oil, these findings will be readily translated into clinical practice.
Publisher: Research Square Platform LLC
Date: 03-08-2019
Abstract: Background: Knee osteoarthritis (OA) is a common and important cause of pain and disability, but interventions aimed at structural modification have been disappointing. While OA affects the whole joint, synovitis and effusion have been recognised as having a role in the pathogenesis of OA. Krill oil reduces knee pain and systemic inflammation and could be used for targeting inflammatory mechanisms of OA. Methods: 260 patients with clinical knee OA, significant knee pain and effusion-synovitis present on MRI will be recruited in 5 Australian cities (Hobart, Melbourne, Sydney, Adelaide and Perth). They will be randomly allocated to the two arms of the study, receiving 2g/day krill oil or inert placebo daily for 6 months. MRI of the study knee will be performed at screening, and after 6 months. Knee symptoms, function and MRI structural abnormalities will be assessed using validated methods. Safety data will be recorded. Primary outcomes are absolute change in knee pain (assessed by visual analog score) and change in size of knee effusion-synovitis over 24 weeks. Secondary outcomes include improvement in knee pain over 4, 8, 12, 16 and 20 weeks. The primary analyses will be intention-to-treat analyses of primary and secondary outcomes. Per protocol analyses adjusting for missing data and for treatment compliance will be performed as the secondary analyses. Discussion: This study will provide high-quality evidence to assess whether krill oil 2g/day reduces pain and effusion-synovitis size in older adults with clinical knee OA and knee effusion-synovitis. If krill oil is effective and confirmed to be safe, we will provide compelling evidence that krill oil improves pain and function, changes disease trajectory and slows disease progression in OA. Given the lack of approved therapies for slowing disease progression in OA, and moderate cost of krill oil, these findings will be readily translated into clinical practice.
Publisher: Research Square Platform LLC
Date: 09-10-2019
Abstract: Background : Knee osteoarthritis (OA) is a common and important cause of pain and disability, but interventions aimed at modifying structures visible on imaging have been disappointing. While OA affects the whole joint, synovitis and effusion have been recognised as having a role in the pathogenesis of OA. Krill oil reduces knee pain and systemic inflammation and could be used for targeting inflammatory mechanisms of OA. Methods : 260 patients with clinical knee OA, significant knee pain and effusion-synovitis present on MRI will be recruited in 5 Australian cities (Hobart, Melbourne, Sydney, Adelaide and Perth). They will be randomly allocated to the two arms of the study, receiving 2g/day krill oil or inert placebo daily for 6 months. MRI of the study knee will be performed at screening, and after 6 months. Knee symptoms, function and MRI structural abnormalities will be assessed using validated methods. Safety data will be recorded. Primary outcomes are absolute change in knee pain (assessed by visual analog score) and change in size of knee effusion-synovitis over 24 weeks. Secondary outcomes include improvement in knee pain over 4, 8, 12, 16 and 20 weeks. The primary analyses will be intention-to-treat analyses of primary and secondary outcomes. Per protocol analyses adjusting for missing data and for treatment compliance will be performed as the secondary analyses. Discussion : This study will provide high-quality evidence to assess whether krill oil 2g/day reduces pain and effusion-synovitis size in older adults with clinical knee OA and knee effusion-synovitis. If krill oil is effective and confirmed to be safe, we will provide compelling evidence that krill oil improves pain and function, changes disease trajectory and slows disease progression in OA. Given the lack of approved therapies for slowing disease progression in OA, and moderate cost of krill oil, these findings will be readily translated into clinical practice.
Publisher: MDPI AG
Date: 29-01-2016
Publisher: Elsevier
Date: 2013
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2017
Publisher: National Institute of Industrial Health
Date: 2017
Publisher: Oxford University Press (OUP)
Date: 02-2003
DOI: 10.1093/RHEUMATOLOGY/KEG073
Abstract: To understand the factors that influence joint cartilage in health and disease as they are important for the prevention and management of osteoarthritis. We conducted a cross-sectional study to determine factors influencing knee cartilage volume in 45 males aged (mean+/-S.D.) 52.5+/-13.2 yr. Total and medial tibial volumes were inversely associated with age, body mass index (BMI) and amount of physical activity and positively associated with total bone content. BMI explained the largest amount of the variation in tibial cartilage volume (18.7%). There were similar findings at the lateral tibial cartilage, but for age and total bone content this did not reach statistical significance. There was a positive association with serum testosterone at all tibial cartilage sites, but this only reached statistical significance for medial tibial cartilage, where serum testosterone explained up to 8% of the variation in cartilage volume. Modifiable risk factors of osteoarthritis also appear to be significant determinants of tibial cartilage volume. Serum testosterone may provide one possible explanation for gender differences in tibial cartilage volume and prevalence of tibiofemoral osteoarthritis. The proposed link between osteoarthritis and knee cartilage volume and the effect of testosterone will need to be confirmed in longitudinal studies.
Publisher: Wiley
Date: 20-03-2022
DOI: 10.1111/AJO.13507
Abstract: There is now robust evidence that when women settle to sleep on their back in late pregnancy ( weeks) they are at increased risk of stillbirth. Therefore, there are several stillbirth prevention programs worldwide that have begun advising pregnant women to adopt a side position when settling to sleep in late pregnancy. However, some hold concerns that giving women information about sleep position and stillbirth risk may make them anxious. This study aimed to determine what influences how ‘safe sleep’ messages are perceived by pregnant women and if there is anxiety associated with receiving this message. An online survey of 537 Australian women ( n = 97 were ‘currently pregnant’). The survey examined participant’s views regarding sleep position messages, type of information source as well as participant characteristics such as general anxiety and their fetal health locus of control (FHLC). Our findings suggest that the FHLC may influence how health messaging regarding sleep in pregnancy is perceived and acted upon. We have also shown a subset of pregnant women may feel anxiety associated with the sleep position in pregnancy message. This may not be related to history of anxiety, but rather to their higher ‘internal’ FHLC, ie those who reflect a greater sense of personal agency over fetal health. Our findings suggest most women will perceive information about settling into sleep position as informative rather than anxiety provoking. Therefore, maternity care providers should not be overly concerned about provoking anxiety when providing this information.
Publisher: Informa UK Limited
Date: 03-2004
DOI: 10.1080/03009740310004612
Abstract: Knee cartilage volume measurement requires significant time and training. Simplifying the measurement may improve feasibility. We investigated whether the area of cartilage shown on the middle slice of the medial and lateral tibial cartilages on sagittal MRI correlates with radiological features of osteoarthritis (OA), cartilage volume, and longitudinal change in cartilage volume. One hundred and seventy-three subjects (normal and osteoarthritic), who had serial magnetic resonance imaging (cartilage volume measured) and baseline weight-bearing antero-posterior radiographs of the same knee were examined. In the lateral compartment, with increasing grade of OA there was a significant reduction in cartilage area. In the medial compartment, this was true for medial joint-space narrowing (after adjusting for gender). There was a moderate to strong association between cartilage area and volume, especially in those with early or no OA. However, when change over time was examined, the strength of these relationships was weak. Our data suggests that cartilage area may provide a simple surrogate measure of cartilage volume, in cross-sectional studies, after adjustment for gender: especially in subjects with early disease. However, before it can be widely used, further investigation will be required.
Publisher: Research Square Platform LLC
Date: 04-08-2021
DOI: 10.21203/RS.3.RS-725139/V1
Abstract: Background To describe the longitudinal associations between the morphological parameters of proximal tibiofibular joint (PTFJ) and joint structural changes in tibiofemoral compartments in patients with knee osteoarthritis (OA). Methods The participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. PTFJ morphological parameters were measured on coronal and sagittal MRI. The contacting area (S) of PTFJ, and its projection areas onto the horizontal (load-bearing area, Sτ), sagittal (lateral stress-bolstering area, Sφ) and coronal plane (posterior stress-bolstering area, Sυ) were assessed. Knee structural abnormalities, including cartilage defects, bone marrow lesions (BMLs) and cartilage volume, were evaluated at baseline and after 2 years. Log binominal regression models and linear regression models were used to assess the associations between PTFJ morphological parameters and osteoarthritic structural changes. Results In the longitudinal analyses, the S (RR: 1.45) and Sτ (RR: 1.55) of PTFJ were significantly and positively associated with an increase in medial tibial (MT) cartilage defects. The Sτ (β: -0.07), Sυ (β: -0.07), and S (β: -0.06) of PTFJ were significantly and negatively associated with changes in MT cartilage volume. The Sτ (RR: 1.55) of PTFJ was positively associated with an increase in MT BMLs, and Sφ (RR: 0.35) was negatively associated with an increase in medial femoral BMLs. Conclusions This longitudinal study suggests that higher load-bearing area of PTFJ could be a risk factor for structural changes in medial tibiofemoral (MTF) compartment in knee OA. This may provide a theoretical support for proximal fibular osteotomy in the treatment of MTF OA. Trial registration: Clinicaltrials.gov Identifier: NCT01176344 Anzctr.org.au Identifier: ACTRN12610000495022Date of registration: 7 May 2010
Publisher: Elsevier BV
Date: 12-2004
DOI: 10.1016/J.SEMARTHRIT.2004.07.007
Abstract: There is some observational evidence to suggest an effect of hormones on osteoarthritis (OA), especially in perimenopausal women. To review the epidemiological evidence for an effect of estrogen replacement therapy (ERT) on the incidence and prevalence of OA, especially radiological OA, and the effect of ERT on articular cartilage in women. The literature relating to these questions was reviewed using OVID Medline (1966 to March 2003). Some studies which have suggested a protective effect of ERT on the incidence and prevalence of OA. However, many of the confidence intervals include unity. Although a protective effect also was seen on articular knee cartilage in long-term users of ERT compared with never users, no difference in change in cartilage was seen over 2 years. There is weak epidemiological evidence suggesting a role for estrogen therapy in joint health in postmenopausal women. The data are more suggestive of an effect on large joint OA than small joint OA.
Publisher: BMJ
Date: 07-2005
Publisher: Informa UK Limited
Date: 03-03-2020
Publisher: Wiley
Date: 02-2005
DOI: 10.1002/ART.20791
Abstract: Although obesity is widely accepted as a risk factor for knee osteoarthritis, it is not clear whether in idual components of body composition, such as the mass and distribution of muscle and fat, are associated with development of the disease. This study examined the effect of measures of body composition on the longitudinal change in tibial cartilage volume. Body composition, assessed via dual x-ray absorptiometry, and tibial cartilage volume, assessed via magnetic resonance imaging, were measured in 86 healthy men and women who were mid-life in age. Change in tibial cartilage volume was assessed by imaging each knee 2 years after the baseline measurement and determining the difference from baseline in tibial cartilage volume. Correlations were determined between the muscle and fat mass of the arm, leg, and total body and the volume of the lateral- and medial-tibial cartilage, as well as the change in tibial cartilage volume over 2 years, after adjusting for confounders. There was a significant association between muscle mass and the medial-tibial cartilage volume, independent of age, sex, body mass index, tibial bone area, and level of physical activity. Although there was a positive association between muscle mass and the lateral-tibial cartilage volume, this did not persist after adjustment for confounders. Loss of muscle mass was associated with an increased loss of medial- and lateral-tibial cartilage over 2 years, after adjusting for confounders. No relationship was apparent between fat mass and either medial- or lateral-tibial cartilage volume, or between fat mass and change in either medial- or lateral-tibial cartilage volume over 2 years, after adjusting for confounders. Muscle mass is an independent predictor of medial-tibial cartilage volume in healthy people in mid-life and is associated with a reduction in the rate of loss of tibial cartilage. This suggests that increased muscle mass may be protective against the onset of osteoarthritis.
Publisher: Wiley
Date: 19-09-2019
DOI: 10.1111/CSP2.111
Publisher: BMJ
Date: 04-2022
DOI: 10.1136/BMJOPEN-2021-060520
Abstract: Shift workers are at an increased risk of developing obesity and type 2 diabetes. Eating and sleeping out of synchronisation with endogenous circadian rhythms causes weight gain, hyperglycaemia and insulin resistance. Interventions that promote weight loss and reduce the metabolic consequences of eating at night are needed for night shift workers. The aim of this study is to examine the effects of three weight loss strategies on weight loss and insulin resistance (HOMA-IR) in night shift workers. A multisite 18-month, three-arm randomised controlled trial comparing three weight loss strategies continuous energy restriction and two intermittent fasting strategies whereby participants will fast for 2 days per week (5:2) either during the day (5:2D) or during the night shift (5:2N). Participants will be randomised to a weight loss strategy for 24 weeks (weight loss phase) and followed up 12 months later (maintenance phase). The primary outcomes are weight loss and a change in HOMA-IR. Secondary outcomes include changes in glucose, insulin, blood lipids, body composition, waist circumference, physical activity and quality of life. Assessments will be conducted at baseline, 24 weeks (primary endpoint) and 18 months (12-month follow-up). The intervention will be delivered by research dietitians via a combination of face-to-face and telehealth consultations. Mixed-effect models will be used to identify changes in dependent outcomes (weight and HOMA-IR) with predictor variables of outcomes of group, time and group–time interaction, following an intention-to-treat approach. The study protocol was approved by Monash Health Human Research Ethics Committee (RES 19-0000-462A) and registered with Monash University Human Research Ethics Committee. Ethical approval has also been obtained from the University of South Australia (HREC ID: 202379) and Ambulance Victoria Research Committee (R19-037). Results from this trial will be disseminated via conference presentations, peer-reviewed journals and student theses. Australian New Zealand Clinical Trials Registry (ACTRN-12619001035112).
Publisher: Wiley
Date: 21-02-2012
DOI: 10.1111/J.1742-6723.2012.01533.X
Abstract: To evaluate the effect of working consecutive night shifts on sleep time, prior wakefulness, perceived levels of fatigue and psychomotor performance in a group of Australian emergency registrars. A prospective observational study with a repeated within-subjects component was conducted. Sleep time was determined using sleep diaries and activity monitors. Subjective fatigue levels and reciprocal reaction times were evaluated before and after day and night shifts. A total of 11 registrars participated in the study with 120 shifts analysed. Sleep time was found to be similar during consecutive night and day shifts. The mean number of hours spent awake before the end of a night shift was 14.33. Subjective fatigue scores were worst at the end of a night shift. There was no difference in reciprocal reaction time between the end of night shift and the start of day shift. Registrars sleep a similar amount of time surrounding night and day shifts. Despite reporting the highest levels of fatigue at the end of a night shift, there is no significant difference in reaction times at the end of night shift compared with the beginning of day shift. This correlates with the finding that at the end of night shift the registrars have been awake for less than 16 h, which is the point at which psychomotor performance is expected to decline.
Publisher: Cold Spring Harbor Laboratory
Date: 16-05-2023
DOI: 10.1101/2023.05.15.23289982
Abstract: Increasing physical activity (PA) is an effective strategy to slow reductions in cortical volume and maintain cognitive function in older adulthood. However, PA does not exist in isolation, but coexists with sleep and sedentary behaviour to make up the 24-hour day. We investigated how the balance of all three behaviours (24-hour time-use composition) is associated with grey matter volume in healthy older adults, and whether grey matter volume influences the relationship between 24-hour time-use composition and cognitive function. This cross-sectional study included 378 older adults (65.6 ± 3.0 years old, 123 male) from the ACTIVate study across two Australian sites (Adelaide and Newcastle). Time-use composition was captured using 7-day accelerometry, and T1-weighted magnetic resonance imaging was used to measure grey matter volume both globally and across regions of interest (ROI: frontal lobe, temporal lobe, hippoc i, and lateral ventricles). Pairwise correlations were used to explore univariate associations between time-use variables, grey matter volumes and cognitive outcomes. Compositional data analysis linear regression models were used to quantify associations between ROI volumes and time-use composition, and explore potential associations between the interaction between ROI volumes and time-use composition with cognitive outcomes. After adjusting for covariates (age, sex, education), there were no significant associations between time-use composition and any volumetric outcomes. There were significant interactions between time-use composition and frontal lobe volume for long-term memory (p=0.018) and executive function (p=0.018), and between time-use composition and total grey matter volume for executive function (p=0.028). Spending more time in moderate-vigorous PA was associated with better long-term memory scores, but only for those with smaller frontal lobe volume (below the s le mean). Conversely, spending more time in sleep and less time in sedentary behaviour was associated with better executive function in those with smaller total grey matter volume. Although 24-hour time use was not associated with total or regional grey matter independently, total grey matter and frontal lobe grey matter volume mediated the relationship between time-use composition and several cognitive outcomes. Future studies should investigate these relationships longitudinally to assess whether changes in time-use composition correspond to changes in grey matter volume and cognition.
Publisher: Elsevier BV
Date: 03-2007
DOI: 10.1016/J.APERGO.2006.03.006
Abstract: Fatigue is a serious issue for the rail industry, increasing inefficiency and accident risk. The performance of 20 train drivers in a rail simulator was investigated at low, moderate and high fatigue levels. Psychomotor vigilance (PVT), self-rated performance and subjective alertness were also assessed. Alertness, PVT reaction times, extreme speed violations (>25% above the limit) and penalty brake applications increased with increasing fatigue level. In contrast, fuel use, draft (stretch) forces and braking errors were highest at moderate fatigue levels. Thus, at high fatigue levels, errors involving a failure to act (errors of omission) increased, whereas incorrect responses (errors of commission) decreased. The differential effect of fatigue on error types can be explained through a cognitive disengagement with the virtual train at high fatigue levels. Interaction with the train reduced dramatically, and accident risk increased. Awareness of fatigue-related performance changes was moderate at best. These findings are of operational concern.
Publisher: Elsevier BV
Date: 2018
Publisher: Wiley
Date: 06-2008
Publisher: Bentham Science Publishers Ltd.
Date: 05-2007
Publisher: Wiley
Date: 23-05-2023
DOI: 10.1002/CB.2182
Abstract: The social and environmental impacts of the global fashion industry face increasing scrutiny. As such, consumers and brands look towards ‘sustainable fashion’ for low‐impact alternatives. Simultaneously, visual social media platforms such as Instagram have become prevalent places for fashion advertising and discourse. To investigate this under‐researched area, the current study utilises visual content and social network analysis to explore how sustainable fashion is presented on Instagram, specifically: (a) what visual characteristics are present within sustainable fashion content, and (b) in what broader contexts and communities is discussion of sustainable fashion taking place? Posts included under the hashtag #sustainablefashion ( N = 650) were inspected for visual characteristics, including type of clothing, presence of person, post setting, presence of nature, and post format. Most posts were photographs located indoors with no person and no nature‐based elements. The hashtags used alongside #sustainablefashion were analysed with Gephi software to establish a social network and community groups of related topics. Network analysis revealed four key community groups: online‐promotional, artisan‐traditional, eco‐ethical, and Malay‐online‐selling. Secondhand fashion also appeared to be the most prominent sustainable fashion alternative on Instagram. This study is one of the first to investigate the characteristics of user‐generated #sustainablefashion content on Instagram. Whilst social media is a burgeoning avenue for research, existing studies primarily investigate how these platforms can be harnessed for advertising, rather than what users themselves are already posting. Implications for brands who use this platform and opportunities for future research are discussed.
Publisher: Public Library of Science (PLoS)
Date: 23-12-2014
Publisher: Springer Science and Business Media LLC
Date: 28-11-2011
Publisher: Informa UK Limited
Date: 02-01-2019
DOI: 10.1080/00140139.2018.1527951
Abstract: Verbal protocol analysis (VPA) is often used to elicit information about the cognitive processes of operators as it provides rich data and can be used in naturalistic settings. Recently VPA has been used to investigate the acquisition and maintenance of situation awareness (SA), and to make comparisons between groups despite a lack of research regarding the efficacy of using VPA for this purpose. This train simulator experiment investigated whether VPA can effectively measure SA. Novice and expert participants were recorded on an audio device while talking aloud throughout the trials and their verbalisations were transcribed verbatim. A coding scheme developed from the transcripts was used to code the verbalisations. Results did not support the use of VPA as a measure of SA but did show that VPA detected differences in SA errors. Potential reasons for the conflicting findings between this experiment and those conducted by other researchers are discussed. Practitioner summary: This paper examined the validity of verbal protocol analysis (VPA) as a situation awareness (SA) measure. A repeated measures experiment was conducted using a train simulator. Normal VPA did not detect changes in SA but a measure of errors did. Caution should be used when using VPA to measure SA. Abbreviations: LETSSA: low-event task subjective situation awareness technique SA: situation awareness SAGAT: situation awareness global assessment technique TPD: train performance display VPA: verbal protocol analysis.
Publisher: Elsevier BV
Date: 07-2011
DOI: 10.1016/J.JVOICE.2010.10.020
Abstract: When a person is sleep deprived, someone who knows them and their usual voice may comment that they sound tired, often supporting their observation with comments, which may include, "you sound croaky" or "rough," or "you don't sound too bright," (meaning the voice and not intellectual capacity) or "you sound down" or "flat." To explore the concept that fatigue may produce such recognizable, consistent, and measurable voice changes, a study was designed in which 15 participants underwent 24 hours of sleep deprivation. They were recorded at specific intervals reading a standard passage and the results indicated that the voices deteriorated. The team of trained listener judges perceived the voices as sounding more tired, specifically rougher and less brilliant and the acoustic analysis revealed that the mean fundamental frequency fell, providing some validation for the comments "croaky," "not so bright," and "down," respectively. To explore the possibility of prevention of such deterioration, the participants subsequently received a specific voice training, followed by a second, identical sleep deprivation study. The results of the second, posttraining sleep deprivation study indicated that the voices had become more resilient to the effects of sleep deprivation. The results are discussed in light of the fact that such deterioration as a consequence of sleep deprivation may compromise the quality of vocal performance, contributing to vocal disorder, proving costly should it result in absence from work. Furthermore, for those fatigued in iduals for whom a robust voice is essential, there may be a way to "fatigue proof" the voice.
Publisher: Wiley
Date: 31-07-2019
DOI: 10.1111/COBI.13386
Abstract: Conservation marketing holds potential as a means to engage audiences with bio ersity conservation and help to address the human dimensions of bio ersity loss. Empirical evaluations of conservation marketing indicatives are growing, so we reviewed the literature on this research to inform future directions in the field. We used a systematic search strategy to identify studies that evaluated the effects of conservation marketing interventions (techniques and c aigns) on psychosocial outcomes, categorized as cognitive, affective, or behavioral. Six academic databases (Business Source Complete, Communication & Mass Media Complete, Greenfile, Proquest, Scopus, and Web of Science Core Collections), 3 gray‐literature databases (BASE, Zenodo, and Google Scholar), and 2 websites (Rare and WildAid) were searched. Articles were subjected to critical appraisal to assess their methodological quality, and data were extracted from each article and analyzed using narrative synthesis. Altogether 28 studies from 26 articles were included in the review. Twenty‐five studies were conducted from 2014 through 2016. Methodological quality of most studies was weak ( n = 16, 57%) (moderate quality n = 8, 29% high quality n = 4, 14%). The proportion of studies that evaluated a conservation‐marketing technique (e.g., variants of texts, images, or videos) versus a c aign (e.g., community‐based c aigns targeting locally relevant issues, such as unsustainable palm oil agriculture, light pollution, or wood fuel fire use) was relatively balanced. Although many studies reported statistically significant results in the intended direction, the utility of findings was limited by persistent methodological limitations, such as a lack of a comparator group, use of non‐validated assessment tools, and a focus on self‐reported data and subjective outcomes. Conservation marketing is clearly a nascent field of scientific enquiry that warrants further, high‐quality research investigations.
Publisher: Elsevier BV
Date: 07-2022
Publisher: InTech
Date: 02-05-2012
DOI: 10.5772/31626
Publisher: Informa UK Limited
Date: 20-08-2020
Publisher: Springer Science and Business Media LLC
Date: 22-07-2010
Publisher: Springer Science and Business Media LLC
Date: 10-03-2022
DOI: 10.1038/S41598-022-07627-0
Abstract: Train drivers work long hours on 24 h schedules and many factors impact their fatigue risk at work, creating a clear imperative for good rostering practice. Adopting a systems approach, this study investigated the relationship between multiple interrelated factors (train drivers’ schedule, sleep, wellbeing, and fatigue) and the perceived influence of these factors on train driving performance and safety using an online survey distributed in Australia and New Zealand. In addition to demographics and work schedule, passenger and freight train drivers ( n = 751) answered questions about: (1) Sleep duration (2) wellbeing, including physical and mental health, the extent to which shiftwork causes sleep, social, domestic, and work problems, and (3) the extent to which ten fatigue, health and wellbeing factors in the work and home environment negatively impact their driving performance. The key factor that emerged from analyses, with the largest and most consistent negative effects (and controlling for other factors) was schedule irregularity. Approved rosters were ranked as having the most important impact on day-to-day driving performance, followed by physical and mental health, and outside work factors. Results also suggested that schedule irregularity may lify the negative impacts of the roster, impaired physical and mental health, and outside work factors on driving performance. As shift variability and schedule irregularity are often poorly represented in existing industry guidance, these results provide evidence for increased reflection on current fatigue management guidelines for train drivers and suggest a need for greater focus on schedule irregularity through the lens of a systems approach.
Publisher: MDPI AG
Date: 06-10-2019
DOI: 10.3390/NU11102383
Abstract: There is evidence to indicate that the central biological clock (i.e., our endogenous circadian system) plays a role in physiological processes in the body that impact energy regulation and metabolism. Cross-sectional data suggest that energy consumption later in the day and during the night is associated with weight gain. These findings have led to speculation that when, as well as what, we eat may be important for maintaining energy balance. Emerging literature suggests that prioritising energy intake to earlier during the day may help with body weight maintenance. Evidence from tightly controlled acute experimental studies indicates a disparity in the body’s ability to utilise (expend) energy equally across the day and night. Energy expenditure both at rest (resting metabolic rate) and after eating (thermic effect of food) is typically more efficient earlier during the day. In this review, we discuss the key evidence for a circadian pattern in energy utilisation and balance, which depends on meal timing. Whilst there is limited evidence that simply prioritising energy intake to earlier in the day is an effective strategy for weight loss, we highlight the potential benefits of considering the role of meal timing for improving metabolic health and energy balance. This review demonstrates that to advance our understanding of the contribution of the endogenous circadian system toward energy balance, targeted studies that utilise appropriate methodologies are required that focus on meal timing and frequency.
Publisher: Wiley
Date: 06-2000
DOI: 10.1046/J.1365-2869.2000.00195.X
Abstract: The present study aimed to systematically investigate the effects of elevated fatigue levels on the ability to self-monitor performance. Eighteen participants, aged 19-26 y, remained awake for a period of 28 h. Neurobehavioural performance was measured at hourly intervals using four tests from a standardized computer test battery. From these four tests, six measures of performance were obtained: grammatical reasoning (accuracy and response latency) vigilance (accuracy and response latency) simple sensory comparison and tracking. In addition, before and after each test, participants completed visual analogue scales which required them to rate their alertness level and the speed and accuracy of their performance. In idual test results for both self-ratings and neurobehavioural performance were converted to z-scores. Planned comparison analysis indicated that scores on four of the six performance measures decreased significantly as hours of wakefulness increased. Similarly, predicted performance scores for all six measures of performance decreased significantly. Analysis revealed moderate correlations between predicted and actual performance for the four parameters affected by fatigue. Furthermore, moderate to high correlations were found between all six performance parameters and their respective post-test self-ratings. In addition, moderate to high correlations were found between predicted performance and alertness. Taken together, these findings suggest that as fatigue levels increase, subjects globally assess performance decrements. Results suggest that subjective alertness may in part mediate an in idual's global assessment of performance.
Publisher: Springer Science and Business Media LLC
Date: 11-01-2021
Publisher: Informa UK Limited
Date: 12-2011
Publisher: Wiley
Date: 19-02-2007
DOI: 10.1111/J.1365-2869.2007.00563.X
Abstract: This study investigated the effects of fatigue on train driving using data loggers on 50 locomotives operated by pairs of male train drivers (24-56 years) on an Adelaide-Melbourne corridor. Drivers' work history was used to calculate a fatigue score using Fatigue Audit Interdyne Software. Trains were assigned to one of three groups, based on drivers' maximum fatigue score: low (n = 15), moderate (n = 22) or high (n = 13) fatigue. Changes in driving parameters at different fatigue levels were investigated. A significant (P < 0.05) increase in fuel use was observed. Drivers in the moderate fatigue group used 4% more, and drivers in the high group used 9% more fuel than drivers in the low group. As these trains run daily, taking horsepower into account, this represents an approximate extra weekly cost of AUD$3512 using high compared with low fatigue drivers. High fatigue-group drivers used less throttle and dynamic brake and engaged in more heavy brake and maximum speed violations. Comparison of three, 100 km track sub-sections with undulating, flat, and hilly grade indicated that fuel use increases occurred primarily during the undulating sub-section, and heavy brake and maximum speed violations occurred primarily in the flat sub-section. Fatigued driving becomes less well-planned, resulting in reduced efficiency (e.g. increased fuel consumption) and safety (e.g. braking and speeding violations). Fatigue may manifest differentially depending on track grade. In certain areas, fatigue will cause increased fuel use and economic cost, and in others, reduced safety through driving violations. These factors should be carefully examined in future railway operator research.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.AAP.2018.01.026
Abstract: Self-assessment is the most common method for monitoring performance and safety in the workplace. However, discrepancies between subjective and objective measures have increased interest in physiological assessment of performance. In a double-blind placebo-controlled study, 23 healthy adults were randomly assigned to either a placebo (n = 11 5 F, 6 M) or caffeine condition (n = 12 4 F, 8 M) while undergoing 50 h (i.e. two days) of total sleep deprivation. In previous work, higher salivary alpha-amylase (sAA) levels were associated with improved psychomotor vigilance and simulated driving performance in the placebo condition. In this follow-up article, the effects of strategic caffeine administration on the previously reported diurnal profiles of sAA and performance, and the association between sAA and neurobehavioural performance were investigated. Participants were given a 10 h baseline sleep opportunity (monitored via standard polysomnography techniques) prior to undergoing sleep deprivation (total sleep time: placebo = 8.83 ± 0.48 h caffeine = 9.01 ± 0.48 h). During sleep deprivation, caffeine gum (200 mg) was administered at 01:00 h, 03:00 h, 05:00 h, and 07:00 h to participants in the caffeine condition (n = 12). This strategic administration of caffeine gum (200 mg) has been shown to be effective at maintaining cognitive performance during extended wakefulness. Saliva s les were collected, and psychomotor vigilance and simulated driving performance assessed at three-hour intervals throughout wakefulness. Caffeine effects on diurnal variability were compared with previously reported findings in the placebo condition (n = 11). The impact of caffeine on the circadian profile of sAA coincided with changes in neurobehavioural performance. Higher sAA levels were associated with improved performance on the psychomotor vigilance test during the first 24 h of wakefulness in the caffeine condition. However, only the association between sAA and response speed (i.e. reciprocal-transform of mean reaction time) was consistent across both days of sleep deprivation. The association between sAA and driving performance was not consistent across both days of sleep deprivation. Results show that the relationship between sAA and reciprocal-transform of mean reaction time on the psychomotor vigilance test persisted in the presence of caffeine, however the association was relatively weaker as compared with the placebo condition.
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.APERGO.2016.05.016
Abstract: Residential support workers (RSW) engage in overnight "sleepover" shifts as well as more traditional "standup" night shifts. While research has investigated the consequences of night and on-call work for sleep in other industries, the sleep of RSW has not been evaluated. In a single-provider case study, six employees completed the Pittsburgh Sleep Quality Index (PSQI), the Depression Anxiety Stress Scale (DASS), a 2-week sleep diary, and a 30 min interview, and four also completed the Shirom-Melamed Burnout Measure (SMBM). Participants reported sleep of poor quality, low-mild DASS scores, and evidence of SMBM scores that were elevated relative to norms. Sleep was significantly lower (p < 0.01) following "standup" shifts (mean = 4.1, SD = 1.8 h) and during "sleepover" shifts (mean = 5.6, SD = 2.0 h) compared to non-shift nights (mean = 7.3, SD = 2.3 h). Interviews suggested that sleep fluctuates with level of patient care, colleague assistance, stress, and the quality of the sleeping environment (including bed comfort, light, noise and perceived safety). Findings suggest that this group have sleep that is insufficient and of poor quality and that they may be at risk of burnout. Consideration of ways to optimise sleeping conditions at work (e.g. through noise or stress reduction) would be beneficial. Research in this area has the potential to facilitate improvements in health and safety in this growing industry.
Publisher: BMJ
Date: 02-2005
Publisher: Springer Science and Business Media LLC
Date: 18-05-2022
DOI: 10.1038/S41598-022-08996-2
Abstract: Sleep and fatigue were investigated in aviation search and rescue, firefighting, emergency medical services and offshore transfer operations in 210 participants, for 21 days each, across 17 datasets in seven countries. Sleep data were collected using wrist-worn actigraphs and sleep diaries. Sustained attention was assessed using a 5-min Psychomotor Vigilance Task (PVT). Duty information was provided from corporate IT systems. Despite the number of 24 h operations, most work occurred during daytime hours, and most sleep occurred at night. There were seasonal changes in work and sleep patterns, with naps used to augment total sleep time. The proportion of sleep occurring during duty varied from zero to 30%. Differences in PVT response times were trivial to small. Legislation that defines flight, duty time and minimum rest limits assume that sleep is not obtained during duty periods, apart from some napping under Fatigue Risk Management Systems (FRMS). However, especially in cases where the aviation service requires waiting for tasks (e.g. search and rescue, emergency medical response), this assumption may not always hold. FRMS should accommodate different modes of working that safely facilitate sleep during duty time where appropriate.
Publisher: Cambridge University Press
Date: 14-02-2017
Publisher: Wiley
Date: 04-11-2005
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.PHYSBEH.2019.02.004
Abstract: Sleep loss is one of the most common causes of accidents and errors in operational environments. Currently, no single method satisfies all of the requisite criteria of an effective system for assessing the risk of injury prior to safety being compromised. Research has concentrated towards the development of a biomarker for in idualized assessment of sleepiness-related deficits in neurobehavioral alertness, with salivary alpha-amylase (sAA) recently reported as a potential biomarker during acute total sleep deprivation. The present study extends on previous research by investigating the association between sAA and neurobehavioral alertness during simulated night-shift work, during in iduals are required to work at night when biological processes are strongly promoting sleep and sleep during the day when endogenous processes are promoting wakefulness. In a laboratory-controlled environment, 10 healthy non-shift working males aged 24.7 ± 5.3 years (mean ± SD) underwent four consecutive nights of simulated night-shift work. Between 17:30-04:30 h participants provided saliva s les and completed a 3 min psychomotor vigilance test (PVT-B), 40 min simulated driving task, and 3 min digit symbol substitution test (DSST). Higher sAA levels were associated with faster response speed on the PVT-B, reduced lane variability on the simulated driving task, and improved information processing speed on the DSST during the first night-shift. There were no associations between sAA levels and performance outcomes during subsequent night-shifts. Findings indicate that the usability of sAA to assess the risk of neurobehavioral deficits during shift-work operations is limited. However, the robust circadian rhythm exhibited by sAA during the protocol of circadian misalignment suggests that sAA could serve as a potential circadian marker.
Publisher: Wiley
Date: 19-02-2007
DOI: 10.1111/J.1365-2869.2007.00574.X
Abstract: Rate of recovery of daytime performance and sleepiness following moderate and severe sleep deprivation (SD) was examined when recovery opportunity was either augmented or restricted. Thirty healthy non-smokers, aged 18-33 years, participated in one of three conditions: moderate SD with augmented (9-h) recovery opportunities, moderate SD with restricted (6-h) recovery opportunities, or severe SD with augmented recovery opportunities. Each participant attended the laboratory for 8-9 consecutive nights: an adaptation and baseline night (23:00-08:00 hours), one or two night(s) of wakefulness, and five consecutive recovery sleep opportunities (23:00-08:00 hours or 02:00-08:00 hours). On each experimental day, psychomotor vigilance performance (PVT) and subjective sleepiness (SSS) were assessed at two-hourly intervals, and MSLTs were performed at 1000 h. PSG data was collected for each sleep period. For all groups, PVT performance significantly deteriorated during the period of wakefulness, and sleepiness significantly increased. Significant differences were observed between the groups during the recovery phase. Following moderate SD, response speed, lapses and SSS returned to baseline after one 9-h sleep opportunity, while sleep latencies required two 9-h opportunities. When the recovery opportunity was restricted to six hours, neither PVT performance nor sleepiness recovered, but stabilised at below-baseline levels. Following severe SD, sleepiness recovered after one (SSS) or two (physiological) 9-h sleep opportunities, however PVT performance remained significantly below baseline for the entire recovery period. These results suggest that the mechanisms underlying the recovery process may be more complicated than previously thought, and that we may have underestimated the impact of sleep loss and/or the restorative value of subsequent sleep.
Publisher: Elsevier BV
Date: 02-2017
DOI: 10.1016/J.AAP.2015.11.009
Abstract: Short, nighttime naps are used as a fatigue countermeasure in night shift work, and may offer protective benefits on the morning commute. However, there is a concern that nighttime napping may impact upon the quality of daytime sleep. The aim of the current project was to investigate the influence of short nighttime naps ( 0.05). Short nighttime naps did not significantly affect daytime recovery total sleep time (p>0.05). Slow wave sleep (SWS) obtained during the 30-min nighttime nap resulted in a significant reduction in SWS during subsequent daytime recovery sleep (p<0.05), such that the total amount of SWS in 24-h was preserved. Therefore, short naps did not protect against performance decrements during a simulated morning commute, but they also did not adversely affect daytime recovery sleep following a night shift. Further investigation is needed to examine the optimal timing, length or combination of naps for reducing performance decrements on the morning commute, whilst still preserving daytime sleep quality.
Publisher: Springer International Publishing
Date: 2021
Publisher: Scandinavian Journal of Work, Environment and Health
Date: 23-06-2015
DOI: 10.5271/SJWEH.3509
Abstract: The aim of this review was to identify which limited wake shift work schedules (LWSW) best promote sleep, alertness, and performance. LWSW are fixed work/rest cycles where the time-at-work does is ≤8 hours and there is >1 rest period per day, on average, for ≥2 consecutive days. These schedules are commonly used in safety-critical industries such as transport and maritime industries. Literature was sourced using PubMed, Embase, PsycInfo, Scopus, and Google Scholar databases. We identified 20 independent studies (plus a further 2 overlapping studies), including 5 laboratory and 17 field-based studies focused on maritime watch keepers, ship bridge officers, and long-haul train drivers. The measurement of outcome measures was varied, incorporating subjective and objective measures of sleep: sleep diaries (N=5), actigraphy (N=4), and polysomnography, (N=3) sleepiness: Karolinska Sleepiness Scale (N=5), visual analog scale (VAS) alertness (N=2) and author-derived measures (N=2) and performance: Psychomotor Vigilance Test (PVT) (N=5), Reaction Time or Vigilance tasks (N=4), Vector and Letter Cancellation Test (N=1), and subjective performance (N=2). Of the three primary rosters examined (6 hours-on/6 hours-off, 8 hours-on/8 hours-off and 4 hours-on/8 hours-off), the 4 hours-on/8 hours-off roster was associated with better sleep and lower levels of sleepiness. In iduals working 4 hours-on/8 hours-off rosters averaged 1 hour more sleep per night than those working 6 hours-on/6 hours-off and 1.3 hours more sleep than those working 8 hours-on/8 hours-off (P<0.01). More broadly, findings indicate that LWSW schedules were associated with better sleep and lower sleepines in the case of (i) shorter time-at-work, (ii) more frequent rest breaks, (iii) shifts that start and end at the same clock time every 24 hours, and (iv) work shifts commencing in the daytime (as opposed to night). The findings for performance remain incomplete due to the small number of studies containing a performance measure and the heterogeneity of performance measures within those that did. The literature supports the utility of LWSW in industries where in iduals sleep at or near the workplace as they facilitate at least some sleep during the biological night and minimize deficits associated with time-on-shift with shorter shifts. Overall, the 4 hour-on/8 hour-off roster best promoted sleep and minimized sleepiness compared to other LWSW schedules. Nevertheless, and considering the safety-critical nature of industries which employ LWSW, the limited literature needs to be greatly expanded with specific focus on the consequences for performance and comparison to mainstream rosters.
Publisher: Informa UK Limited
Date: 23-05-2012
DOI: 10.3109/07420528.2012.675848
Abstract: The detrimental effects of excessive alcohol consumption are well documented. There is some evidence that shiftworkers consume more alcohol than dayworkers as a sleep aid to compensate for sleep difficulties associated with work schedules. This study investigated drinking patterns between shiftworkers and dayworkers using the 2006 and 2007 waves from the Household Income and Labour Dynamics Survey. A subset of workers who were not in full-time study and had a single job were selected participants who did not drink alcohol (n = 2090) were excluded. Using the 2001 Australian Government alcohol guidelines, alcohol consumption for risk of short-term harm (7+ standard drinks for men, 5+ for women) was investigated. The number of workers who drank alcohol "nearly every day" or "every day" was also examined. Some 13% of shiftworkers and 10% of those on standard schedules reported consuming alcohol at levels risky for short-term harm. Having a child less than 17 yrs (odds ratio [OR] = .39, 95% confidence interval [CI] = .22-.69), higher job demands (OR = .71, 95% CI = .58-.86), being female (OR = .45, 95% CI=. 26-.79), and being older (OR = .89, 95% CI = .87-.92) significantly reduced, whereas being a shiftworker (OR = 2.10, 95% CI = 1.08-4.12) significantly increased, the odds of drinking alcohol in short-term risky levels. Nearly 10% of shiftworkers and 8% of those on standard schedules reported consuming alcohol in short-term risky levels at least weekly. Having a child less than 17 yrs (OR = .40, 95% CI = .22-.74), higher job demands (OR = .69, 95% CI = .56-.86), being female (OR = .28, 95% CI = .15-.53), and being older (OR = .92, 95% CI = .89-.94) were associated with a significant reduction in the odds of consuming alcohol at risky levels at least weekly. Being a shiftworker was not associated with a significant increase in the odds of consuming alcohol at such risky levels at least weekly, but a trend was evident (OR = 1.47, 95% CI = .73-3.00). Some 13.5% of shiftworkers and 21% of those on standard schedules reported consuming alcohol in any amount "near daily" or "daily." Working more hours than preferred (OR = 1.80, 95% CI = 1.12-2.89) and being older (OR = 1.10, 95% CI = 1.07-1.13) were associated with a significant increase, and being female (OR = .18, 95% CI = .10-.33), and being a shiftworker (OR = .20, 95% CI = .09-.45) were associated with a significant decrease in the odds of consuming alcohol "daily" or "near daily." Overall, the results suggest that shiftworkers may be more likely to consume alcohol at levels considered to be risky for health in the short term. In contrast, they appear less likely to drink alcohol daily. This pattern is suggestive of "binge drinking" behavior.
Publisher: Cambridge University Press (CUP)
Date: 14-03-2022
No related grants have been discovered for Jillian Dorrian.