ORCID Profile
0000-0002-7691-9289
Current Organisations
University of South Australia
,
Queensland University of Technology
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Publisher: IOP Publishing
Date: 11-02-2004
Publisher: IOP Publishing
Date: 21-04-2005
Publisher: Wiley
Date: 16-12-2023
DOI: 10.1111/JGS.18181
Abstract: Objective measures for screening, prioritizing, and planning care for frail in iduals are essential for appropriate aged care provision. This study evaluates metrics derived from actigraphy measures (captured by wrist accelerometer) as a digital biomarker to identify frail in iduals at risk of adverse outcomes, including death, hospitalization, and cognitive decline. This was a secondary study using data from a randomized controlled trial assessing the effectiveness of an ongoing pharmacist service in residential aged care facilities. Three metrics are studied and compared: the Frailty Index, the daily time spent in light time activity, and the temporal correlation of the actigraphy signal, measured by detrended fluctuation analysis. The association between actigraphy‐derived metrics at baseline and adverse events within 12 months (death, cognitive decline, and hospitalizations) was assessed using logistic regression. Actigraphy records were available for 213 participants living in aged‐care, median age of 85 years. In iduals with higher temporal correlation (activity is less random) were at lower risk of death (Standardized OR: 0.49 95% CI 0.34, 0.7, p 0.001) and hospitalization (Standardized OR: 0.57 95% CI 0.42, 0.77, p 0.001) in 12 months, but there was no difference in cognitive decline (Standardized OR: 1 95% CI 0.74, 1.35, p = 0.98). The predictive model that included temporal correlation had an area under the curve of 0.70 (CI 0.60–0.80) for death and 0.64 (CI 0.54–0.72) for hospitalization. Temporal correlation of the actigraphy signal from aged care residents was strongly associated with death and hospitalization, but not cognitive decline. Digital biomarkers may have a place as an objective, accurate, and low‐cost patient metric to support risk stratification and clinical planning.
Publisher: Wiley
Date: 04-07-2022
DOI: 10.1111/AJO.13577
Abstract: Nitrous oxide is commonly used in Australia for labour analgesia. Its use in labour is potentially associated with aerosol generation. During the first wave of the COVID‐19 pandemic of 2020, nitrous oxide was suspended on many birthing units to reduce the risk of transmission. We aimed to determine the impact of withholding nitrous oxide for labour analgesia, during the COVID‐19 pandemic, on epidural rates, opioid analgesia use, and maternal and neonatal outcomes. Withholding nitrous oxide for labour analgesia did not alter epidural rates but did significantly increase opioid analgesia use. Caesarean section rates, post‐partum blood loss and neonatal APGAR scores did not change.
Publisher: Wiley
Date: 14-09-2022
Abstract: To test the equivalence of two doses of intravenous iron (ferric carboxymaltose) in pregnancy. Parallel, two‐arm equivalence randomised controlled trial with an equivalence margin of 5%. Single centre in Australia. 278 pregnant women with iron deficiency. Participants received either 500 mg ( n = 152) or 1000 mg ( n = 126) of intravenous ferric carboxymaltose in the second or third trimester. The proportion of participants requiring additional intravenous iron (500 mg) to achieve and maintain ferritin microg/L (diagnostic threshold for iron deficiency) at 4 weeks post‐infusion, and at 6 weeks, and 3‐, 6‐ and 12‐months postpartum. Secondary endpoints included repeat infusion rate, iron status, birth and safety outcomes. The two doses were not equivalent within a 5% margin at any time point. At 4 weeks post infusion, 26/73 (36%) participants required a repeat infusion in the 500‐mg group compared with 5/67 (8%) in the 1000‐mg group: difference in proportions, 0.283 (95% confidence interval [CI] 0.177–0.389). Overall, participants in the 500‐mg arm received twice the repeat infusion rate (0.81 [SD = 0.824] versus 0.40 [SD = 0.69], rate ratio 2.05, 95% CI 1.45–2.91). Administration of 1000 mg ferric carboxymaltose in pregnancy maintains iron stores and reduces the need for repeat infusions. A 500‐ mg dose requires ongoing monitoring to ensure adequate iron stores are reached and sustained.
Publisher: Springer Science and Business Media LLC
Date: 26-05-2023
DOI: 10.1007/S00404-023-07082-W
Abstract: Intraoperative cell salvage is central to Patient Blood Management including for lower segment caesarean section. Prior to April 2020, we initiated intraoperative cell salvage during caesarean section based on risk assessment for hemorrhage and patient factors. As the pandemic broadened, we mandated intraoperative cell salvage to prevent peri-partum anemia and potentially reduce blood product usage. We examined the association of routine intraoperative cell salvage on maternal outcomes. We conducted a single-center non-overlapping before-after study of obstetric patients undergoing lower segment caesarean section in the 2 months prior to a change in practice (‘usual care = selective intraoperative cell salvage’, n = 203) and the 2 months following (‘mandated intraoperative cell salvage’, n = 228). Recovered blood was processed when a minimal autologous reinfusion volume of 100 ml was expected. Post-operative iron infusion and length of stay were modelled using logistic or linear regression, using inverse probability weighting to account for confounding. More emergency lower-segment caesarean sections occurred in the Usual Care group. Compared to the Usual Care group, post-operative hemoglobin was higher and anemia cases fewer in the Mandated intraoperative cell salvage group. Rates of post-partum iron infusion were significantly lower in the Mandated intraoperative cell salvage group (OR = 0.31, 95% CI = 0.12 to 0.80, P = 0.016). No difference was found for length of stay. Routine cell salvage provision during lower segment caesarean section was associated with a significant reduction in post-partum iron infusions, increased post-operative hemoglobin and reduced anemia prevalence.
Publisher: Springer Science and Business Media LLC
Date: 06-09-2015
Publisher: IOP Publishing
Date: 02-1992
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 27-12-2008
Publisher: IEEE
Date: 2006
Publisher: Springer Science and Business Media LLC
Date: 25-06-2019
Publisher: Springer Science and Business Media LLC
Date: 24-08-2021
DOI: 10.1186/S13063-021-05486-0
Abstract: This a priori statistical analysis plan describes the analysis for CRISTAL. CRISTAL (cluster-randomised, crossover, non-inferiority trial of aspirin compared to low molecular weight heparin for venous thromboembolism prophylaxis in hip or knee arthroplasty, a registry nested study) aims to determine whether aspirin is non-inferior to low molecular weight heparin (LMWH) in preventing symptomatic venous thromboembolism (VTE) following hip arthroplasty (HA) or knee arthroplasty (KA). The study is nested within the Australian Orthopaedic Association National Joint Replacement Registry. The trial was commenced in April 2019 and after an unplanned interim analysis, recruitment was stopped (December 2020), as the stopping rule was met for the primary outcome. The clusters comprised hospitals performing 250 HA and/or KA procedures per annum, whereby all adults ( 18 years) undergoing HA or KA were recruited. Each hospital was randomised to commence with aspirin, orally, 85–150 mg daily or LMWH (enoxaparin), 40 mg, subcutaneously, daily within 24 h postoperatively, for 35 days after HA and 14 days after KA. Crossover was planned once the registration target was met for the first arm. The primary end point is symptomatic VTE within 90 days. Secondary outcomes include readmission, reoperation, major bleeding and death within 90 days, and reoperation and patient-reported pain, function and health status at 6 months. The main analyses will focus on the primary and secondary outcomes for patients undergoing elective primary total HA and KA for osteoarthritis. The analysis will use an intention-to-treat approach with cluster summary methods to compare treatment arms. As the trial stopped early, analyses will account for incomplete cluster crossover and unequal cluster sizes. This paper provides a detailed statistical analysis plan for CRISTAL. Australian and New Zealand Clinical Trials Registry ACTRN12618001879257 . Registered on 19/11/2018.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Springer Science and Business Media LLC
Date: 05-04-2022
DOI: 10.1186/S12931-022-02010-Z
Abstract: In elderly populations, paracetamol may be used regularly for conditions such as osteoarthritis. Paracetamol has been associated with respiratory disease through a proposed mechanism of glutathione depletion and oxidative stress. Given that chronic obstructive pulmonary disease (COPD) is frequently co-morbid with osteoarthritis, this study investigated whether the dose and timing of paracetamol exposure may induce COPD exacerbations. The study population was 3523 Australian Government Department of Veterans’ Affairs full entitlement holders who had existing COPD on 1 January 2011, who were dispensed at least one prescription of paracetamol between 1 January 2011 and 30 September 2015, and had no paracetamol dispensed in the 6 months prior to 1 January 2011. The outcome was time to first hospitalisation for COPD exacerbation after initiation of paracetamol. A weighted cumulative exposure approach was used. The association between paracetamol exposure and COPD exacerbation was protective or harmful depending on the dose, duration, and recency of exposure. Compared to non-use, current use at the maximum dose of 4 g daily for 7 days was associated with a lower risk (HR = 0.78, 95% CI = 0.67–0.92) and a higher risk after 30 days (HR = 1.27, 95% CI = 1.06–1.52). Risk declined to baseline after 2 months. For past use, there was a short-term increase in risk on discontinuation depending of dose, duration and time since stopping. Patients and doctors should be aware of the possible risk of COPD exacerbation with higher dose paracetamol 1 to 6 weeks after initiation or discontinuation, but no increased risk after 2 months.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-09-2020
DOI: 10.1097/CORR.0000000000001453
Abstract: The Birmingham Hip Resurfacing (BHR) prosthesis is the most commonly used metal-on-metal hip resurfacing arthroplasty device. The current manufacturer-recommended target demographic for the BHR is male patients, younger than 65 years requiring a femoral head size of ≥ 50 mm. Female patients, older patients, and in iduals with smaller femoral-head diameter (≤ 50 mm) are known to have higher revision rates. Prior studies suggest that the survivorship of the BHR when used in the target demographic is comparable with that of primary conventional THA, but comparing survivorship of the most durable hip resurfacing arthroplasty device to the survivorship of all conventional THA prostheses is not ideal because the THA group comprises a large number of different types of prostheses that have considerable variation in prosthesis survival. A more informative comparison would be with the THA implants with the best survivorship, as this might help address the question of whether survivorship in the BHR target population can be improved by using a well-performing conventional THA. We compared the difference in cumulative percent revision, reasons for revision and types of revision for procedures reported to the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) using the BHR prosthesis (femoral-head size 50 mm) and three conventional THA prostheses identified as having the lowest 10-year cumulative percent revision in the currently recommended BHR target population to ask: (1) Does the BHR have a lower cumulative revision rate than the group of three conventional THA prostheses? (2) Is there a difference in the revision diagnosis between the BHR and the three best conventional THA prostheses? (3) What is the difference in the components used for a revision of a BHR compared with the three best conventional THA prostheses? Data reported to the AOANJRR between September 1, 1999 and December 31, 2018 was used for this analysis. This study period includes almost the entire use of the BHR in Australia. The AOANJRR is a large national joint registry with almost 100% completeness, high accuracy, rigorous validation, and little to no loss to follow-up. The study population included males younger than 65 years that had received one hip replacement procedure for osteoarthritis. All patients with bilateral procedures, no matter the time interval between hips, were excluded. Only BHR prostheses with a femoral-head size ≥ 50 mm and conventional THA prostheses with femoral head sizes ≥ 32 mm and either ceramic-on-ceramic or metal, ceramic, ceramicized metal-on-crosslinked polyethylene (XLPE) bearings were included. These femoral head sizes and bearings were selected because they reflect modern conventional THA practice. There is no difference in the revision rate of these bearings in the AOANJRR. There were 4790 BHR procedures and 2696 conventional THA procedures in the study group. The mean (± SD) age for BHR procedures was 52 ± 7.8 years and 56 ± 7.1 years for conventional THA procedures. All comparative analyses were adjusted for age. Other demographics data including American Society Anesthesiologists (ASA) score and BMI were only included in AOANJRR data collection since 2012 and 2015, respectively, and have not been included in this analysis because of the low use of BHR in Australia since that time. The maximum follow-up was 18.7 years for both groups and mean follow-up of 11.9 years for the BHR and 9.3 years for the conventional THA group. Revision rates were determined using Kaplan-Meier estimates of survivorship to describe the time to the first revision, with censoring at the time of death or closure of the database at the time of analysis. A revision was defined as removal, replacement or addition of any component of a joint replacement. Revisions can be further classified as major revisions (removal of a component articulating with bone—usually the stem and/or the shell) or minor revisions (removal of other components—usually the head and/or the liner). The unadjusted cumulative percent revision after the primary arthroplasty (with 95% confidence intervals) was calculated and compared using Cox proportional hazard models adjusted for age. The BHR prosthesis had a statistically higher rate of all-cause revision at 17 years than the selected conventional THA prostheses (HR 2.77 [95% CI 1.78 to 4.32] p 0.001). The revision diagnoses differed between the groups, with the BHR demonstrating a higher revision rate for loosening after 2 years than the conventional THA protheses (HR 4.64 [95% CI 1.66 to 12.97] p = 0.003), as well as a higher fracture rate during the entire period (HR 2.57 [95% CI 1.24 to 5.33] p = 0.01). There was a lower revision rate for infection for the BHR compared with the THA group in the first 5 years, with no difference between the two groups after this time. All revisions of the BHR were major revisions (such as, removal or exchange of the femoral and/or acetabular components) and this occurred in 4.5% of the primary BHR procedures. Major revision was the most common type of revision for primary THA accounting for 1.7% of all primary THA procedures. Minor revisions (head, inset or both) were undertaken in a further 0.6% of primary THA procedures. Given the increasing revision risk of the BHR compared with better-performing conventional THA prostheses in the target population, we recommend that patients be counseled about this risk. We suggest that a THA with proven low revision rates might be the better choice, particularly for patients who are concerned about implant durability. Well-controlled prospective studies that show appreciable clinically important differences in patient-reported outcomes and functional results favoring the BHR over conventional THA prostheses using modern bearings are needed to justify the use of the BHR in view of this revision risk. Level III, therapeutic study.
Publisher: BMJ
Date: 11-2019
DOI: 10.1136/BMJOPEN-2019-031657
Abstract: Venous thromboembolism (VTE) is a serious complication following hip arthroplasty (HA) and knee arthroplasty (KA). This study aims to determine whether aspirin is non-inferior to low molecular weight heparin (LMWH) in preventing symptomatic VTE following HA and KA. This is a cluster randomised, crossover, non-inferiority, trial nested within the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). The clusters will consist of Australian hospitals performing at least 250 HA and/or KA procedures per annum. All adult patients undergoing HA or KA will be included. The intervention will be aspirin, orally, 85–150 mg daily. The comparator will be LMWH (enoxaparin) 40 mg, subcutaneously, daily. Both drugs will commence within 24 hours postoperatively and continue for 35 days after HA and 14 days after KA. Each hospital will be randomised to commence with aspirin or LMWH and then crossover to the alternative treatment after meeting the recruitment target. Data will be collected through the AOANJRR via patient-reported surveys. The primary outcome is symptomatic VTE within 90 days post surgery, verified by AOANJRR staff. The primary analysis will include only patients undergoing elective primary total hip arthroplasty and total knee arthroplasty for osteoarthritis. Secondary outcomes will include symptomatic VTE for all HA and KA (including partial and revision) within 90 days, readmission, reoperation, major bleeding and death within 90 days and reoperation, death and patient-reported pain, function and health status at 6 months. If aspirin is found to be inferior, a cost-effectiveness analysis will be conducted. The study will aim to recruit 15 562 patients from 31 hospitals. Ethics approval has been granted. Trial results will be submitted for publication. The trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12618001879257, pre-results) and is endorsed by the Australia and New Zealand Musculoskeletal Clinical Trials Network.
Publisher: Optica Publishing Group
Date: 04-1999
DOI: 10.1364/AO.38.001986
Abstract: The broadband performance of a polarization-insensitive liquid-crystal phase modulator is analyzed, and its effect on an adaptive optics system is quantified.
Publisher: Springer Science and Business Media LLC
Date: 17-10-2021
DOI: 10.1186/S12874-021-01408-5
Abstract: Case-crossover studies have been widely used in various fields including pharmacoepidemiology. Vines and Farrington indicated in 2001 that when within-subject exposure dependency exists, conditional logistic regression can be biased. However, this bias has not been well studied. We have extended findings by Vines and Farrington to develop a weighting method for the case-crossover study which removes bias from within-subject exposure dependency. Our method calculates the exposure probability at the case period in the case-crossover study which is used to weight the likelihood formulae presented by Greenland in 1999. We simulated data for the population with a disease where most patients receive a cyclic treatment pattern with within-subject exposure dependency but no time trends while some patients stop and start treatment. Finally, the method was applied to real-world data from Japan to study the association between celecoxib and peripheral edema and to study the association between selective serotonin reuptake inhibitor (SSRI) and hip fracture in Australia. When the simulated rate ratio of the outcome was 4.0 in a case-crossover study with no time-varying confounder, the proposed weighting method and the Mantel-Haenszel odds ratio reproduced the true rate ratio. When a time-varying confounder existed, the Mantel-Haenszel method was biased but the weighting method was not. When more than one control period was used, standard conditional logistic regression was biased either with or without time-varying confounding and the bias increased (up to 8.7) when the study period was extended. In real-world analysis with a binary exposure variable in Japan and Australia, the point estimate of the odds ratio (around 2.5 for the association between celecoxib and peripheral edema and around 1.6 between SSRI and hip fracture) by our weighting method was equal to the Mantel-Haenszel odds ratio and stable compared with standard conditional logistic regression. Case-crossover studies may be biased from within-subject exposure dependency, even without exposure time trends. This bias can be identified by comparing the odds ratio by the Mantel-Haenszel method and that by standard conditional logistic regression. We recommend using our proposed method which removes bias from within-subject exposure dependency and can account for time-varying confounders.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2009
Publisher: Springer Science and Business Media LLC
Date: 14-07-2023
DOI: 10.1007/S40520-023-02491-Y
Abstract: Frailty is increasingly recognised as a dynamic syndrome, with multiple causes, dimensions and consequences. There is little understanding of how those frailty assessment metrics interact over time. The aim of this study was to describe the longitudinal correlation between five frailty metrics, namely multimorbidity, muscular strength, mood alterations, cognitive capacity, and functional capacity in a cohort study of aged care (nursing home) residents. 248 aged care residents with Frailty Index at baseline of 0.4 and no dementia were followed for 12 months. A multimorbidity score and an activity of daily living limitation score were created using in idual items of the Frailty Index. Muscular strength was measured by grip strength. Cognitive capacity was measured using the Montreal Cognitive Assessment (MoCA) test. Mood alterations were measured using the anxiety/depression screening question from EQ-5D. We analysed the inter-in idual correlation at baseline, association between baseline and future change, and within-in idual correlation at baseline, 6 and 12 months. Population analysis shows that metrics were not associated at baseline. All of the studied metrics at baseline were associated with change in 12 months, with the exception of anxiety/depression scores. Pairwise within-in idual correlation was strong between MoCA and grip strength (0.13, p = 0.02) and activity of daily living (− 0.48, p 0.001), and between activities of daily living and multimorbidity index (0.28, p 0.001). No within-in idual correlation was found between anxiety depression score and other metrics. The results suggest an interdependence between comorbidities, physical capacity, cognition and activities of daily living in aged care residents. Comprehensive measurement of frailty-related metrics may provide improved understanding of frailty progression at later life stages.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-04-2023
DOI: 10.1097/CCM.0000000000005861
Abstract: Evidence of cerebrovascular complications in COVID-19 requiring venovenous extracorporeal membrane oxygenation (ECMO) is limited. Our study aims to characterize the prevalence and risk factors of stroke secondary to COVID-19 in patients on venovenous ECMO. We analyzed prospectively collected observational data, using univariable and multivariable survival modeling to identify risk factors for stroke. Cox proportional hazards and Fine-Gray models were used, with death and discharge treated as competing risks. Three hundred eighty institutions in 53 countries in the COVID-19 Critical Care Consortium (COVID Critical) registry. Adult COVID-19 patients who were supported by venovenous ECMO. None. Five hundred ninety-five patients (median age [interquartile range], 51 yr [42–59 yr] male: 70.8%) had venovenous ECMO support. Forty-three patients (7.2%) suffered strokes, 83.7% of which were hemorrhagic. In multivariable survival analysis, obesity (adjusted hazard ratio [aHR], 2.19 95% CI, 1.05–4.59) and use of vasopressors before ECMO (aHR, 2.37 95% CI, 1.08–5.22) were associated with an increased risk of stroke. Forty-eight-hour post-ECMO Pa co 2 –pre-ECMO Pa co 2 re-ECMO Pa co 2 (relative ΔPa co 2 ) of negative 26% and 48-hour post-ECMO Pa o 2 –pre-ECMO Pa o 2 re-ECMO Pa o 2 (relative ΔPa o 2 ) of positive 24% at 48 hours of ECMO initiation were observed in stroke patients in comparison to relative ΔPa co 2 of negative 17% and relative ΔPa o 2 of positive 7% in the nonstroke group. Patients with acute stroke had a 79% in-hospital mortality compared with 45% mortality for stroke-free patients. Our study highlights the association of obesity and pre-ECMO vasopressor use with the development of stroke in COVID-19 patients on venovenous ECMO. Also, the importance of relative decrease in Pa co 2 and moderate hyperoxia within 48 hours after ECMO initiation were additional risk factors.
Publisher: Elsevier BV
Date: 04-2010
DOI: 10.1111/J.1600-6143.2009.03002.X
Abstract: We investigated whether a rejection episode in one graft was associated with rejection in the other graft, in recipients with bilateral corneal transplants. In a prospectively maintained, national register of 14,865 followed corneal grafts, 1476 patients with bilateral penetrating corneal grafts were identified. Occurrence of rejection was a risk factor for graft failure (p < 0.0001). Logistic regression was used to calculate the adjusted odds ratio for rejection in one eye following rejection in the other eye. In the subset of 1118 patients with bilateral grafts but no history of previous grafts or rejections in either eye, the adjusted odds ratio for a rejection episode in the first eye following rejection in the second was 3.27 (95% confidence interval, CI 1.85, 5.79 p < 0.001). The adjusted odds ratio was 2.04 (95% CI 1.07, 3.91 p = 0.03) for rejection in the second eye following rejection in the first. The median time between the first rejection episode in one eye and the first rejection episode in the other eye was 15 months. Patients with bilateral corneal grafts who suffer a graft rejection episode in one eye are at significantly greater odds of suffering a rejection episode in the other corneal transplant.
Publisher: Elsevier BV
Date: 07-2000
Publisher: Wiley
Date: 23-06-2023
DOI: 10.1111/AJR.13012
Abstract: Stroke in Regional Australia may have worse outcomes due to difficulties accessing optimal care. The South Australian Regional Telestroke service aimed to improve telestroke neurologist access, supported by improved ambulance triage. To assess stroke care quality and patient mortality pre‐ and postimplementation of a vascular neurologist‐led Telestroke service. Historically controlled mixed methods cohort study comparing key quality indicators and patient mortality (6 months pre‐ vs. 18 months postimplementation date [4 June 2018]) at the three major South Australian regional stroke centres. The primary outcome was 13 care quality indicators as a combined composite risk‐adjusted score, and the secondary outcome was risk‐adjusted mortality at 12‐month postadmission. On an annualised basis, of 189 patients with stroke, more were admitted postintervention to the regional stroke centres than in the control period (158 [annualised rate 105.3, 95% CI 86.2–127.4] vs. 31 [annualised rate 62.0, 95% CI 47.5–79.5]) Baseline patient characteristics were similar in both periods. Post‐implementation, median last‐known‐well time to presentation (3.5 h [IQR 1.6–17] vs. 2.0 [IQR 1–14] p = 0.46) and door to needle times (121 min [IQR 97–144] vs. 90 [IQR 75–138] p = 0.65) were not significantly lower but an improvement in the combined composite quality score was observed (0.069 [95% CI 0.004–0.134 p = 0.04]), reflecting in idual improvements in some quality indicators. Mortality at 12‐month postimplementation was substantially lower postimplementation (prechange 23% vs. postchange 13% [hazard ratio 0.58 (95% CI 0.44–0.76 p 0.001)]). Implementation of a South Australian Regional Telestroke service was associated with improved care metrics and lower mortality.
Publisher: SAGE Publications
Date: 02-2016
Abstract: Alternative bearings surfaces to Cobalt Chrome (Co-Cr), such as Oxidised have been introduced in an attempt to reduce polyethylene wear and hence decrease TKA loosening and lysis. While non-comparative reports have been described as promising, no short or long term clinical studies exists showing the superiority of Oxinium on a polyethylene bearing surfaces. In this study, we investigate the long-term outcomes of Oxinium and Co-Cr TKR in a “like for like” or matched cohort analysis of the Genesis II design (Smith & Nephew, Memphis, TN, USA). Using data from a large national joint replacement registry we selected cohorts that used only the cruciate retaining design, with the same method of fixation and polyethylene type, differing only in the femoral component bearing surfaces. Our primary hypothesis was that Oxinium TKA would have a lower cumulative percent revision than the same Co-Cr prosthesis at 12 years for all causes of revision. Our secondary hypothesis was that Oxinium TKA would have a lower loosening/ lysis rate and lower rate of non-infective revision than the same Co-Cr prosthesis at 12 years. Cumulative percent revision and revision diagnosis data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 1 September 1999, until 31 December 2013. At 12 years the cumulative percent revision of the Co-Cr Genesis II of 4.8 % (95%: CI 4.2, 5.4) for all causes was not statistically different to the Oxinium Genesis II CPR of 7.7 % (95%: CI 6.2, 9.5) (For the entire period, Hazard Ratio = 1.09 (95%: CI 0.92, 1.29), p = 0.329). The CPR for all causes was not different in the under 55 years old age group (Figure 3) (HR= 1.06 (0.68, 1.66) p=0.798).). Subgroup analysis of the CPR for loosening /lysis in both groups overall was not different (HR= 0.87 (95%: CI 0.61, 1.26), p = 0.461) Subgroup analysis of all causes of revisions excluding infection in both groups overall was not different (HR = 0.87 (95%: CI 0.71, 1.06), p = 0.155) . No difference in CPR was found between the Oxinium and Co-Cr groups for any age category for all causes of revision, loosening/lysis or non-infective causes, except for loosening/lysis in the years old group (p=0.033). In these patients, Oxinium TKA had a higher CPR due to uncertain reasons. In this AOANJRR age stratified matched cohort study, Oxinium femoral components did not reduce revision rates due to all causes, loosening/lysis or when infection as a cause of revision was removed, compared to the same Co-Cr femoral component, across all age groups including patients who were under 55 years of age.
Publisher: American Medical Association (AMA)
Date: 09-06-2023
DOI: 10.1001/JAMANETWORKOPEN.2023.17838
Abstract: Ischemic heart disease remains the leading cause of mortality following hip and knee arthroplasty. Due to its antiplatelet and cardioprotective properties, aspirin has been proposed as an agent that could reduce mortality when used as venous thromboembolism (VTE) prophylaxis following these procedures. To compare aspirin with enoxaparin in reducing 90-day mortality for patients undergoing hip or knee arthroplasty procedures. This study was a planned secondary analysis of the CRISTAL cluster randomized, crossover, registry-nested trial performed across 31 participating hospitals in Australia between April 20, 2019, and December 18, 2020. The aim of the CRISTAL trial was to determine whether aspirin was noninferior to enoxaparin in preventing symptomatic VTE following hip or knee arthroplasty. The primary study restricted the analysis to patients undergoing total hip or knee arthroplasty for a diagnosis of osteoarthritis only. This study includes all adult patients (aged ≥18 years) undergoing any hip or knee arthroplasty procedure at participating sites during the course of the trial. Data were analyzed from June 1 to September 6, 2021. Hospitals were randomized to administer all patients oral aspirin (100 mg daily) or subcutaneous enoxaparin (40 mg daily) for 35 days after hip arthroplasty and 14 days after knee arthroplasty procedures. The primary outcome was mortality within 90 days. The between-group difference in mortality was estimated using cluster summary methods. A total of 23 458 patients from 31 hospitals were included, with 14 156 patients allocated to aspirin (median [IQR] age, 69 [62-77] years 7984 [56.4%] female) and 9302 patients allocated to enoxaparin (median [IQR] age, 70 [62-77] years 5277 [56.7%] female). The mortality rate within 90 days of surgery was 1.67% in the aspirin group and 1.53% in the enoxaparin group (estimated difference, 0.04% 95% CI, −0.05%-0.42%). For the subgroup of 21 148 patients with a nonfracture diagnosis, the mortality rate was 0.49% in the aspirin group and 0.41% in the enoxaparin group (estimated difference, 0.05% 95% CI, −0.67% to 0.76%). In this secondary analysis of a cluster randomized trial comparing aspirin with enoxaparin following hip or knee arthroplasty, there was no significant between-group difference in mortality within 90 days when either drug was used for VTE prophylaxis. anzctr.org.au Identifier: ACTRN12618001879257
Publisher: Wiley
Date: 08-05-2019
DOI: 10.1002/SIM.8191
Abstract: Girardeau, Ravaud and Donner in 2008 presented a formula for s le size calculations for cluster randomised crossover trials, when the intracluster correlation coefficient, interperiod correlation coefficient and mean cluster size are specified in advance. However, in many randomised trials, the number of clusters is constrained in some way, but the mean cluster size is not. We present a version of the Girardeau formula for s le size calculations for cluster randomised crossover trials when the number of clusters is fixed. Formulae are given for the minimum number of clusters, the maximum cluster size and the relationship between the correlation coefficients when there are constraints on both the number of clusters and the cluster size. Our version of the formula may aid the efficient planning and design of cluster randomised crossover trials.
Publisher: Frontiers Media SA
Date: 29-08-2022
DOI: 10.3389/FPHAR.2022.978871
Abstract: Aim: To examine the incidence and nature of medicine-related problems over time experienced by nursing home residents. Method: We analyzed records collected in the Reducing Medicine-Induced Deterioration and Adverse Events (ReMInDAR) trial. The trial pharmacists provided services to reduce medicine-induced deterioration and adverse reactions for residents every 8-weeks over a year. The problems identified by the pharmacists were documented in reports and subsequently classified independently by research pharmacists using the D.O.C.U.M.E.N.T system. The number and type of problems at each service and time to develop a new problem post first session were assessed. All analyses were performed using R software (Version 4.1.1). Results: The cohort was 115 nursing home residents who received 575 services. In the 12-months, a total of 673 medicine-related problems or symptom reports were identified in 112 residents. Most residents (75%) experienced a new medicine-related problem by the fourth month post the first assessment. After the first session, the proportion of residents with a new medicine-related problem or symptom report declined at each repeated pharmacy session (59% at visit 2 vs. 28% at visit 6, p & 0.01). Conclusion: Residents living in nursing homes frequently experience medicine-related problems. Our results suggest clinical pharmacist services performed every 4-months may have the potential to reduce the medicine-related problems in nursing homes.
Publisher: Optica Publishing Group
Date: 2007
DOI: 10.1364/OE.15.010370
Abstract: We describe a Hartmann sensor with a sensitivity of lambda /15,500 at lambda= 820nm. We also demonstrate its application to the measurement of an ultra small change in wavefront and show that the result agrees with that expected to within lambda/3,300.
Publisher: Research Square Platform LLC
Date: 16-03-2023
DOI: 10.21203/RS.3.RS-2614829/V1
Abstract: Purpose Intraoperative cell salvage is central to Patient Blood Management including for lower segment caesarean section. Prior to April 2020, we initiated intraoperative cell salvage during caesarean section based on risk assessment for hemorrhage and patient factors. As the pandemic broadened, we mandated intraoperative cell salvage to prevent peri-partum anemia and potentially reduce blood product usage. We examined the association of routine intraoperative cell salvage on maternal outcomes. Methods We conducted a single-center non-overlapping before-after study of obstetric patients undergoing lower segment caesarean section in the 2 months prior to change in practice (‘usual care = selective intraoperative cell salvage’, n = 203) and the 2 months following (‘mandated intraoperative cell salvage’, n = 228). Recovered blood was processed when a minimal autologous reinfusion volume of 100 ml was expected. Post-operative iron infusion and length of stay were modelled using logistic or linear regression, using inverse probability weighting to account for confounding. Results More emergency lower segment caesarean sections occurred in the Usual Care group. Compared to the Usual Care group, post-operative hemoglobin was higher and anemia cases fewer in the Mandated intraoperative cell salvage group. Rates of post-partum iron infusion were significantly lower in the Mandated intraoperative cell salvage group (OR = 0.31, 95% CI = 0.12 to 0.80, P = 0.016). No difference was found for length of stay. Conclusion Routine cell salvage provision during lower segment caesarean section was associated with a significant reduction in post-partum iron infusions, increased post-operative hemoglobin and reduced anemia prevalence.
Publisher: Optica Publishing Group
Date: 02-02-2007
DOI: 10.1364/AO.46.000861
Abstract: A novel differential Hartmann sensor is described. It can be used to determine the characteristics of an optic accurately, precisely, and simply without detailed knowledge of the wavefront used to illuminate the optical system or of the geometry of the measurement system. We demonstrate the application of this sensor to both zonal and modal optical testing of lenses. We also describe a dual-camera implementation of the sensor that would enable high-speed optical testing.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 30-07-2021
Publisher: Springer Science and Business Media LLC
Date: 09-2005
Publisher: Elsevier BV
Date: 08-2011
DOI: 10.1016/J.OPHTHA.2011.01.002
Abstract: To determine factors influencing penetrating corneal graft survival in patients receiving repeat grafts in the same eye after a failed first graft for keratoconus. Large cohort study from a national register of corneal grafts, in which data were recorded prospectively and analyzed retrospectively. Follow-up extended to 23 years. Follow-up was available for 229 regrafts performed in 177 eyes of 173 patients. Regrafts were performed more than once in 16 eyes. Corneal graft survival was analyzed using Kaplan-Meier survival plots and Cox proportional hazards regression, clustered by patient. Graft survival. Graft survival was significantly worse (P<0.001) for second (n = 176) and third or greater grafts (n = 20), compared with first grafts for keratoconus (n = 4871). Kaplan-Meier survivals at 1, 5, and 15 years postgrafting were 88%, 69%, and 46% for second grafts, and 65%, 49%, and 33% for third and subsequent grafts, respectively (P<0.001). Risk factors associated with graft failure of repeat grafts in multivariate analysis were the geographic location of surgery ("center" P = 0.04), failure of the previous graft within 10 years of surgery (P = 0.02), recipient age at graft ≥60 years (P = 0.04), occurrence of rejection episodes (P = 0.007), and corneal neovascularization postoperatively (P = 0.007). Repeat corneal grafts in eyes originally grafted for keratoconus showed better survival when the previous graft had survived ≥10 years, surgery was performed at a favorable location, the recipient was <60 years old at grafting, and graft rejection and neovascularization were circumvented. The authors have no proprietary or commercial interest in any of the materials discussed in this article.
Publisher: Wiley
Date: 25-09-2023
DOI: 10.1002/PDS.5701
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 15-02-2017
Abstract: This article was updated on March 8, 2017, because of a previous error. On page 275, in the Results section of the abstract, the sentence that had read “No difference in the HR for revision risk was found between the Oxinium and CoCr cohorts for any age category for all causes of revision (HR = 0.92 [95% confidence interval (CI), 0.92 to 1.29] p = 0.329), loosening or lysis, or aseptic causes, except for loosening or lysis in the group of patients who were ≥75 years old (p = 0.033)” now reads “No difference in the HR for revision risk was found between the Oxinium and CoCr cohorts for any age category for all causes of revision (HR = 0.92 [95% confidence interval (CI), 0.78 to 1.08] p = 0.329), loosening or lysis, or aseptic causes, except for loosening or lysis in the group of patients who were ≥75 years old (p = 0.033).” On page 276, in Figure 1, the text that had read “Entire Period: HR = 0.92 (0.92, 1.29), p = 0.329” now reads “Entire Period: HR = 0.92 (0.78, 1.08), p = 0.329.” On page 279, in the Results section, the sentence that had read “There was no significant difference between Oxinium and CoCr with respect to the rate of revision (HR = 0.92 [95% CI, 0.92 to 1.29] p = 0.329) (Fig. 1)” now reads “There was no significant difference between Oxinium and CoCr with respect to the rate of revision (HR = 0.92 [95% CI, 0.78 to 1.08] p = 0.329) (Fig. 1).” An erratum has been published: J Bone Joint Surg Am. 2017 Apr 5 (7):e37. Oxidized zirconium (Oxinium) was introduced as an alternative bearing surface to cobalt-chromium (CoCr) in an attempt to reduce polyethylene wear and decrease aseptic mechanical failure of total knee replacements. While noncomparative reports have been described as promising, we were aware of no short or long-term clinical studies showing the superiority of Oxinium on polyethylene as a bearing surface. Using data from a comprehensive national joint replacement registry, we compared the long-term outcomes after cruciate-retaining total knee arthroplasty (TKA) with an Oxinium femoral component and those with the same prosthetic design but with a CoCr femoral component. The cohorts consisted of 17,577 cemented Genesis-II cruciate-retaining total knee replacements using non-cross-linked polyethylene, which included 11,608 with CoCr femoral components and 5,969 with Oxinium femoral components. The cumulative percent revision and hazard ratio (HR) for revision risk were estimated for the cemented Genesis-II Oxinium and CoCr cruciate-retaining TKAs performed in Australia from September 1, 1999, to December 31, 2013. In addition, the revision diagnoses and the effects of age and patellar resurfacing were examined. No difference in the HR for revision risk was found between the Oxinium and CoCr cohorts for any age category for all causes of revision (HR = 0.92 [95% confidence interval (CI), 0.78 to 1.08] p = 0.329), loosening or lysis, or aseptic causes, except for loosening or lysis in the group of patients who were ≥75 years old (p = 0.033). In these patients, TKA with Oxinium femoral components had a higher rate of revision. Younger patients preferentially received Oxinium femoral components. The revision risk was not affected by patellar resurfacing or nonresurfacing. At 12 years, the cumulative percent revision was 4.8% (95% CI, 4.2% to 5.4%) for the CoCr Genesis-II prosthesis compared with 7.7% (95% CI, 6.2% to 9.5%) for the Oxinium Genesis-II prosthesis. In this cohort study involving the same prosthetic design, Oxinium femoral components did not reduce revision rates for all causes, loosening or lysis, or when infection as a cause of revision was removed compared with the same CoCr femoral component across all age groups including patients who were years old. The cumulative percent revision was greater for the Oxinium components than for the CoCr components. Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.
Publisher: American Medical Association (AMA)
Date: 13-06-2011
DOI: 10.1001/ARCHOPHTHALMOL.2011.7
Abstract: To determine factors influencing long-term graft survival and visual acuity in 4834 eyes of 4060 patients receiving their first penetrating corneal graft for keratoconus. A large cohort study was performed from a national register of corneal grafts in which data were recorded prospectively and analyzed retrospectively. Main outcome measures were graft survival and Snellen visual acuity. Follow-up extended up to 23 years. Kaplan-Meier survival rates of first grafts for keratoconus were 89%, 49%, and 17% at 10, 20, and 23 years, respectively. After 15 years, the graft survival rate was no better than that of all other penetrating grafts (P = .36). Multivariate risk factors influencing failure of first grafts for keratoconus included time to suture removal, postgraft uveitis or microbial keratitis, corneal vascularization prior to or after graft, geographic location of surgery and follow-up (center effect), recipient age at graft, occurrence of rejection episodes, graft size, and surgeon workload. The timing of bilateral grafts made no difference to the risk of rejection. A Snellen visual acuity of 20/40 or better at the most recent follow-up was recorded in 74% of grafts. Penetrating grafts performed for keratoconus exhibited better visual outcome and graft survival than grafts performed for other indications. However, the Kaplan-Meier survival rate of first penetrating grafts for keratoconus was 17% at 23 years after graft and had not plateaued at this time, indicating that young patients are likely to need 1 or more repeated grafts during their lifetime.
Publisher: BMJ
Date: 04-2020
DOI: 10.1136/BMJOPEN-2019-032851
Abstract: Many medicines have adverse effects which are difficult to detect and frequently go unrecognised. Pharmacist monitoring of changes in signs and symptoms of these adverse effects, which we describe as medicine-induced deterioration, may reduce the risk of developing frailty. The aim of this trial is to determine the effectiveness of a 12-month pharmacist service compared with usual care in reducing medicine-induced deterioration, frailty and adverse reactions in older people living in aged-care facilities in Australia. The reducing medicine-induced deterioration and adverse reactions trial is a multicentre, open-label randomised controlled trial. Participants will be recruited from 39 facilities in South Australia and Tasmania. Residents will be included if they are using four or more medicines at the time of recruitment, or taking more than one medicine with anticholinergic or sedative properties. The intervention group will receive a pharmacist assessment which occurs every 8 weeks. The pharmacists will liaise with the participants’ general practitioners when medicine-induced deterioration is evident or adverse events are considered serious. The primary outcome is a reduction in medicine-induced deterioration from baseline to 6 and 12 months, as measured by change in frailty index. The secondary outcomes are changes in cognition scores, 24-hour movement behaviour, grip strength, weight, percentage robust, pre-frail and frail classification, rate of adverse medicine events, health-related quality of life and health resource use. The statistical analysis will use mixed-models adjusted for baseline to account for repeated outcome measures. A health economic evaluation will be conducted following trial completion using data collected during the trial. Ethics approvals have been obtained from the Human Research Ethics Committee of University of South Australia (ID:0000036440) and University of Tasmania (ID:H0017022). A copy of the final report will be provided to the Australian Government Department of Health. Australian and New Zealand Trials Registry ACTRN12618000766213.
Publisher: Frontiers Media SA
Date: 03-11-2022
DOI: 10.3389/FMED.2022.1010444
Abstract: Large population-based studies examining frailty trajectory found a linear increase in frailty over time. The pattern in which frailty changes over time for an in idual person is less well-described. We examined the frailty trajectory of older adults living in aged-care in Australia. This secondary study used data from a randomised controlled trial involving 39 aged-care facilities in Australia. The trial intervention was an on-going pharmacist-led intervention occurring every 8 weeks over 12 months aimed at preventing medicine-induced deterioration and adverse reactions. Frailty was assessed using the Frailty Index. Participants were categorised as non-frail, pre-frail and frail. In idual frailty trajectory over 12 months was visualised using the alluvial plot. Case notes were examined to explore reasons for any rapid transitions in frailty status. A total of 248 participants was included. At baseline, 40.3% were non-frail and 59.7% were pre-frail. The proportion of participants who were non-frail and pre-frail decreased over time 15.7% were frail at 6 months and 23.4% were frail at 12 months. Overall, twenty different combinations of frailty transitions were identified over 12 months. Retrospective analysis of case notes suggest that death or transition from non-frail to frail was often preceded by hospitalisation, falls, medication change or clinically significant deterioration in grip strength or cognition. The degree of frailty increased over time, but there were variations in the in idual trajectories. Regular monitoring of events that precede changes in frailty status is needed to identify strategies to prevent further deterioration in residents’ conditions.
Publisher: Oxford University Press (OUP)
Date: 04-2022
Abstract: To assess the effectiveness of a pharmacist-led intervention using validated tools to reduce medicine-induced deterioration and adverse reactions. Multicenter, open-label parallel randomised controlled trial involving 39 Australian aged-care facilities. Residents on ≥4 medicines or ≥1 anticholinergic or sedative medicine. Pharmacist-led intervention using validated tools to detect signs and symptoms of medicine-induced deterioration which occurred every 8 weeks over 12 months. Usual care (Residential Medication Management Review) provided by accredited pharmacists. Primary outcome was change in Frailty Index at 12 months. Secondary outcomes included changes in cognition, 24-hour movement behaviour by accelerometry, grip strength, weight, adverse events and quality of life. 248 persons (median age 87 years) completed the study 120 in the interventionand, 128 in control arms. In total 575 pharmacist, sessions were undertaken in the intervention arm. There was no statistically significant difference for change in frailty between groups (mean difference: 0.009, 95% CI: −0.028, 0.009, P = 0.320). A significant difference for cognition was observed, with a mean difference of 1.36 point change at 12 months (95% CI: 0.01, 2.72, P = 0.048). Changes in 24-hour movement behaviour, grip strength, adverse events and quality of life were not significantly different between groups. Point estimates favoured the intervention arm at 12 months for frailty, 24-hour movement behaviour and grip strength. The use of validated tools by pharmacists to detect signs of medicine-induced deterioration is a model of practice that requires further research, with promising results from this trial, particularly with regards to improved cognition.
Publisher: BMJ
Date: 09-2022
DOI: 10.1136/BMJOPEN-2022-064478
Abstract: Hip fractures treated with total hip arthroplasty (THA) are at high risk of prosthesis instability, and dislocation is the most common indication for revision surgery. This study aims to determine whether dual mobility THA implants reduce the risk of dislocation compared with conventional THA in patients with hip fracture suitable to be treated with THA. This is a cluster-randomised, crossover, open-label trial nested within the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). The clusters will comprise hospitals that perform at least 12 THAs for hip fracture per annum. All adults age ≥50 years who meet the Australian and New Zealand Hip Fracture Registry guidelines for THA will be included. The intervention will be dual mobility THA and the comparator will be conventional THA. Each hospital will be allocated to two consecutive periods, one of dual mobility THA and the other of conventional THA in random order, aiming for an average of 16 patients eligible for the primary analysis per group (32 total per site), allowing different recruitment totals between sites. Data will be collected through the AOANJRR and linked with patient-level discharge data acquired through government agencies. The primary outcome is dislocation within 1 year. Secondary outcomes include revision surgery for dislocation and all-cause, complications and mortality at 1, 2 and 5 years. If dual mobility THA is found to be superior, a cost-effectiveness analysis will be conducted. The study will aim to recruit 1536 patients from at least 48 hospitals over 3 years. Ethics approval has been granted (Sydney Local Health District - Royal Prince Alfred Hospital Zone (approval X20-0162 and 2020/ETH00680) and site-specific approvals). Participant recruitment is via an opt-out consent process as both treatments are considered accepted, standard practice. The trial is endorsed by the Australia and New Zealand Musculoskeletal Clinical Trials Network. ACTRN12621000069853.
Publisher: SPIE
Date: 29-09-2004
DOI: 10.1117/12.581300
Publisher: Cambridge University Press (CUP)
Date: 2003
DOI: 10.1071/AS03036
Abstract: An enormous effort is underway worldwide to attempt to detect gravitational waves. If successful, this will open a new frontier in astronomy. An essential portion of this effort is being carried out in Australia by the Australian Consortium for Interferometric Gravitational Astronomy (ACIGA), with research teams working at the Australia National University, University of Western Australia, and University of Adelaide involving scientists and students representing many more institutions and nations. ACIGA is developing ultrastable high-power continuous-wave lasers for the next generation interferometric gravity wave detectors researching the problems associated with high optical power in resonant cavities opening frontiers in advanced interferometry configurations, quantum optics, and signal extraction and is the world's leader in high-performance vibration isolation and suspension design. ACIGA has also been active in theoretical research and modelling of potential astronomical gravitational wave sources, and in developing data analysis detection algorithms. ACIGA has opened a research facility north of Perth, Western Australia, which will be the culmination of these efforts. This paper briefly reviews ACIGA's research activities and the prospects for gravitational wave astronomy in the southern hemisphere.
Publisher: British Institute of Radiology
Date: 1994
DOI: 10.1259/0007-1285-67-793-54
Abstract: The International Commission on Radiation Protection have recently recommended an annual dose limit for the skin of radiation workers of 500 mSv at a depth of 20-100 microns averaged over any 1 cm2 regardless of the area exposed. It has previously been shown by the authors that beta dose rates on the outer surfaces of typical laboratory containers (vials, test tubes) or on medical syringes can exceed 100 mSv h-1 for radionuclide concentrations of the order of 1 MBq g-1, depending on container diameter, wall thickness and material and the beta particle energy spectrum. Since the fingers are frequently in contact with such containers it is of some importance to extend these dose calculations to depths below the skin surface, taking into consideration the anatomy of skin on the fingers. Using an extension of a Monte Carlo method previously described, dose rates have been calculated for the clinically useful radionuclides 90Y, 32P, 198Au, 153Sm and 131I. For polypropylene syringes the beta dose rates at a depth of 270 microns (a typical basal cell depth in the fingers) range from 77 to 135 mGy h-1 per MBq g-1 for 90Y (maximum energy 2.27 MeV) and approximately zero to 0.62 mGy h-1 per MBq g-1 for 131I (maximum energy 0.61 MeV). These results emphasize the importance of adequate finger protection when using high energy beta emitters and especially for clinicians who typically inject specific activities of the order of 100 MBq g-1 of 32P in such cases annual permissible dose rates are exceeded in a matter of minutes. It is recommended that a minimum of 5 mm perspex finger protection be used for 90Y and 32P.
Publisher: Oxford University Press (OUP)
Date: 21-04-2023
DOI: 10.1093/AJE/KWAD104
Abstract: The case-crossover study design has been proposed as a suitable design for use when a brief exposure causes a transient change in risk of an acute-onset disease. In pharmacoepidemiology, the condition of “brief exposure” is rarely satisfied because medication use is often chronic or successive, which may result in bias due to within-subject exposure dependency. Here we describe a simulation of a case-crossover study conducted within a cohort, where patients successively used a drug for 60 or more days and the rate ratio for the outcome occurrence was 4.0. Standard conditional logistic regression for the analysis produced overestimated odds ratios ranging up to 7.8. This bias due to within-subject exposure dependency from chronic use can be removed by the Mantel-Haenszel method or by our recently proposed weighting method. We also show that when some patients are censored after switching to another drug, a lack of pairwise exchangeability causes bias which is similar to bias due to an exposure time trend. This bias can be removed by using the case–time-control study design. We show that bias due to within-subject exposure dependency and lack of pairwise exchangeability occur independently and can occur separately or simultaneously, and we demonstrate how to detect and remove them.
Publisher: Springer Science and Business Media LLC
Date: 19-04-2023
Publisher: Optica Publishing Group
Date: 08-1998
DOI: 10.1364/AO.37.005184
Abstract: A phase-aberration-correction system that uses high-resolution, twisted nematic liquid-crystal spatial light modulators in a Mach-Zehnder interferometer is presented. A correction algorithm is described and experimentally verified by use initially of one liquid-crystal panel. Phase aberrations are successfully removed by a single liquid-crystal panel, but unacceptably high litude variation is introduced into the wave front because of the phase- litude coupling of the spatial light modulator. A second panel is used to remove the litude modulation. The modified optical system with a multiplicative architecture is described, and results are presented that show the correction of phase aberrations with an litude variation of less than 10%.
Publisher: Wiley
Date: 09-2009
DOI: 10.1111/J.1442-9071.2009.02116.X
Abstract: To present the outcomes of various retinal conditions treated with the sutureless 25-gauge (25G) vitrectomy technique. Retrospective case review of 232 eyes of 228 patients who underwent 25G vitrectomy from January 2003 to August 2006. Follow-up was a minimum of 3 months. Indications for surgery included idiopathic macular hole, rhegmatogenous retinal detachment, epiretinal membrane and proliferative diabetic retinopathy. Main outcome measures included final visual acuity, re-operation rate and surgical complications such as endophthalmitis, hypotony and retinal (re)detachment. For all cases, the mean overall visual acuity (logMAR) improved from 0.9 preoperatively to 0.5 (P < 0.0001). The improvement in acuity was highest in the rhegmatogenous detachment and diabetic groups. Transient postoperative hypotony was observed in 15 cases (9.2%) on day 1 after surgery but all these cases resolved. In 7.3% of the cases (17 out of 232) additional surgery was performed due to retina (re)detachment but final anatomic success was achieved in all cases the detachments occurred within the first 3 months. One patients developed endophthalmitis (0.4%) which coincided with subconjunctival antibiotics being discontinued in favour of topical treatment. The 25G system remains a safe and effective technique for a variety of retinal conditions significant fast visual rehabilitation is an advantage.
Publisher: American Medical Association (AMA)
Date: 23-08-2022
Abstract: There remains a lack of randomized trials investigating aspirin monotherapy for symptomatic venous thromboembolism (VTE) prophylaxis following total hip arthroplasty (THA) or total knee arthroplasty (TKA). To determine whether aspirin was noninferior to enoxaparin in preventing symptomatic VTE after THA or TKA. Cluster-randomized, crossover, registry-nested trial across 31 hospitals in Australia. Clusters were hospitals performing greater than 250 THA or TKA procedures annually. Patients (aged ≥18 years) undergoing hip or knee arthroplasty procedures were enrolled at each hospital. Patients receiving preoperative anticoagulation or who had a medical contraindication to either study drug were excluded. A total of 9711 eligible patients were enrolled (5675 in the aspirin group and 4036 in the enoxaparin group) between April 20, 2019, and December 18, 2020. Final follow-up occurred on August 14, 2021. Hospitals were randomized to administer aspirin (100 mg/d) or enoxaparin (40 mg/d) for 35 days after THA and for 14 days after TKA. Crossover occurred after the patient enrollment target had been met for the first group. All 31 hospitals were initially randomized and 16 crossed over prior to trial cessation. The primary outcome was symptomatic VTE within 90 days, including pulmonary embolism and deep venous thrombosis (DVT) (above or below the knee). The noninferiority margin was 1%. Six secondary outcomes are reported, including death and major bleeding within 90 days. Analyses were performed by randomization group. Enrollment was stopped after an interim analysis determined the stopping rule was met, with 9711 patients (median age, 68 years 56.8% female) of the prespecified 15 562 enrolled (62%). Of these, 9203 (95%) completed the trial. Within 90 days of surgery, symptomatic VTE occurred in 256 patients, including pulmonary embolism (79 cases), above-knee DVT (18 cases), and below-knee DVT (174 cases). The symptomatic VTE rate in the aspirin group was 3.45% and in the enoxaparin group was 1.82% (estimated difference, 1.97% 95% CI, 0.54%-3.41%). This failed to meet the criterion for noninferiority for aspirin and was significantly superior for enoxaparin ( P = .007). Of 6 secondary outcomes, none were significantly better in the enoxaparin group compared with the aspirin group. Among patients undergoing hip or knee arthroplasty for osteoarthritis, aspirin compared with enoxaparin resulted in a significantly higher rate of symptomatic VTE within 90 days, defined as below- or above-knee DVT or pulmonary embolism. These findings may be informed by a cost-effectiveness analysis. ANZCTR Identifier: ACTRN12618001879257
Publisher: Cold Spring Harbor Laboratory
Date: 11-08-2020
DOI: 10.1101/2020.08.11.20172478
Abstract: An accurate measure of the impact of COVID-19 is the infection fatality ratio, or the proportion of deaths among those infected, which does not depend on variable testing rates between nations. The risk of mortality from COVID-19 depends strongly on age and current estimates of the infection fatality ratio do not account for differences in national age profiles. Comparisons of cumulative death trajectories allow the effect and timing of public health interventions to be assessed. Our purpose is to (1) determine whether countries are clustered according to infection fatality ratios and (2) compare interventions to slow the spread of the disease by clustering death trajectories. National age standardised infection fatality ratios were derived from age stratified estimates from China and population estimates from the World Health Organisation. The IFRs were clustered into groups using Gaussian mixture models. Trajectory analysis clustered cumulative death rates in two time windows, 50 and 100 days after the first reported death. Infection fatality ratios from 201 nations were clustered into three groups: young, medium and older, with corresponding means (SD) of 0.20% (0.03%), 0.38% (0.11%) and 0.93% (0.21%). At 50 and 100 days after the first reported death, there were two clusters of cumulative death trajectories from 113 nations with at least 25 deaths reported at 100 days. The first group had slowly increasing or stable cumulative death rates, while the second group had accelerating rates at the end of the time window. Fifty-two nations changed group membership between the time windows. A cluster of younger nations have a lower estimated infection fatality ratio than older nations. The effect and timing of public health interventions in preventing the spread of the disease can be tracked by clustering death rate trajectories into stable or accelerating and comparing changes over time.
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.RBMO.2019.02.003
Abstract: Does the addition of human growth hormone (HGH) to an IVF cycle improve the live birth rate in previously documented poor responders to FSH? Double-blind, placebo-controlled, randomized clinical trial comparing HGH to placebo in maximal stimulation in an IVF cycle. The study was stopped after 4 years. Women receiving ovarian stimulation in one IVF cycle, having failed to produce more than 5 eggs in a previous cycle with more than 250 IU/day of FSH were included. Basal FSH was ≤15 IU/l, body mass index <33 kg/m The live birth rates following an IVF cycle were 9/62 (14.5%) for growth hormone and 7/51 (13.7%) for the placebo group (risk difference 0.8%, 95% confidence interval [CI] -12.1 to 13.7% odds ratio [OR] 1.07, 95% CI 0.37-3.10). There was a greater odds of oocyte retrieval with growth hormone (OR 5.67, 95% CI 1.54-20.80) but no better chance of embryo transfer (OR 1.42, 95% CI 0.50-4.00). Birth weights were comparable. Planned participant numbers were not reached. It was not possible to demonstrate an increase in live birth rate from the addition of growth hormone in women with a previous poor ovarian response to IVF.
Publisher: Wiley
Date: 23-04-2023
DOI: 10.1111/ANS.18470
Abstract: KRAS and BRAF testing is currently recommended in metastatic colorectal cancer. There is evidence that KRAS and BRAF mutation status may act as a prognostic biomarker in patients with non‐metastatic colorectal cancer. Data is limited on whether KRAS and BRAF mutation status impacts recurrence and mortality in patients with non‐metastatic colorectal cancer. A retrospective cohort study was conducted in a tertiary hospital examining outcomes in patients who had KRAS and BRAF testing for colorectal cancer in 2017. Primary outcomes were all‐cause mortality and recurrence. Multivariable analysis for both outcomes, used cause specific Cox proportional hazards models with KRAS/BRAF status as exposure. For time to recurrence, a sensitivity analysis was performed with a weighted Fine‐Grey model with death as a competing risk. KRAS mutation status was not associated with all‐cause mortality (average Hazard Ratio (aHR) = 0.78, 95% CI 0.28–2.21) or recurrence (aHR = 0.96, 95% CI 0.32–2.86). BRAF mutation status was not associated with time to all‐cause mortality (aHR = 3.06, 95% CI 0.79–11.8) or recurrence (aHR = 0.94, 95% CI 0.13–6.57). Increased risk of recurrence was significantly associated with large bowel obstruction (aHR = 2.73, 95% CI 1.16–6.45) and anaemia (aHR = 3.39, 95% CI 1.06–10.8) at time of surgery. This study did not demonstrate an association between KRAS and BRAF mutations and all‐cause mortality or recurrence. A significantly increased risk of cancer recurrence was found in patients with large bowel obstruction and in patients with anaemia at time of surgery. Anaemia should be promptly investigated and corrected prior to colorectal cancer surgery.
Location: Australia
No related grants have been discovered for Lan Kelly.