Publication
How much does sleep vary from night‐to‐night? A quantitative summary of intraindividual variability in sleep by age, gender, and racial/ethnic identity across eight‐pooled datasets
Publisher:
Wiley
Date:
10-07-2022
DOI:
10.1111/JSR.13680
Abstract: Habitual sleep duration and efficiency vary widely by age, gender, and racial/ethnic identity. Despite growing research on the importance of night‐to‐night, intrain idual variability (IIV) in sleep, few studies have examined demographic differences in sleep IIV. The present study describes typical sleep IIV overall and by demographics among healthy sleepers. Eight datasets of healthy sleepers ( N = 2,404 26,121 total days of sleep data) were synthesised to examine age, gender, and racial/ethnic identity differences in sleep IIV measured via diaries, actigraphy, and electroencephalography (EEG). Sleep IIV estimates included the intrain idual standard deviation (iSD), root mean square of successive differences (RMSSD), coefficient of variation (CV), and a validated Bayesian Variability Model (BVM). There was substantial IIV in sleep across measurement types (diary, actigraphy, EEG) for both sleep duration (iSD: 85.80 [diary], 77.41 [actigraphy], 67.04 [EEG] minutes RMSSD: 118.91, 108.89, 91.93 minutes CV: 19.19%, 19.11%, 18.57% BVM: 60.60, 58.20, 48.60 minutes) and sleep efficiency (iSD: 5.18% [diary], 5.22% [actigraphy], 6.46% [EEG] RMSSD: 7.01%, 7.08%, 8.44% CV: 5.80%, 6.27%, 8.14% BVM: 3.40%, 3.58%, 4.16%). Younger adults had more diary and actigraphy sleep duration IIV. Gender differences were inconsistent. White and non‐Hispanic/Latinx adults had less IIV in sleep duration and efficiency compared to racial/ethnic minority groups. Even among healthy sleepers, sleep varies widely from night‐to‐night. Like mean sleep, there also may be disparities in IIV in sleep by demographic characteristics. Study results help characterise normative values of sleep IIV in healthy sleepers.