Summary Habitual sleep duration and efficiency vary widely by age, gender, and racial/ethnic identity. Despite growing research on the importance of night‐to‐night, intraindividual 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 intraindividual 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.

Substantial comorbidity exists between posttraumatic stress disorder and sleep disturbances/disorders. Such comorbidities are understudied in minority groups, including Asian Indians residing in countries outside India. Thus, we synthesized the existing literature specific to this group of Asian Indians to determine (a) prevalence estimates of posttraumatic stress disorder (PTSD) and sleep disturbances/disorders; and (b) PTSD-sleep comorbidity estimates. For this systematic review, we searched four databases (PubMed, PsycInfo, PTSDpubs, Web of Science) using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of 3,796 screened articles, 9 articles (10 studies) met inclusion criteria. Study sample sizes ranged from 11 to 2,112 Asian Indians; studies were conducted in Singapore or Malaysia. No reviewed study examined PTSD. All studies examined sleep disturbances/disorders among Asian Indians; prevalence estimates were: 8.3% to 70.4% for short sleep duration, 2.0% to 22.9% for long sleep duration, 25.9% to 56.3% for poor sleep quality, 3.4% to 67.5% for insomnia diagnosis or probable insomnia, 7.7% for excessive daytime sleepiness, 3.8% to 54.6% for obstructive sleep apnea (OSA) diagnosis or high OSA risk, and 5.1% to 11.1% for sleep-disordered breathing. Specific to Asian Indians residing in countries outside India, this review advances PTSD-sleep literature by (a) suggesting substantial prevalence of sleep disturbances/disorders; (b) highlighting the need for culturally relevant sleep interventions; and (c) highlighting research gaps (e.g., no PTSD-focused research).

The COVID‐19 pandemic has resulted in substantial changes in individual and socio‐economic factors that may negatively impact sleep health. We examined associations between COVID‐19 related distress and sleep among trauma‐exposed South Asian adults in the United States. Since a health advantage among foreign‐born individuals has been previously noted in the literature (the ‘immigrant paradox’), we also explored if generational status (number of generations one's family has been in the U.S.) moderated associations between COVID‐19 related distress and sleep health. Participants were 196 trauma‐exposed South Asian adults residing in the U.S. (54% male, 63% U.S.‐born citizens, average age = 34.51 years), who completed measures of generational status, COVID‐19 related distress, trauma exposure, sleep‐related impairment (SRI), and sleep disturbances. Greater COVID‐19 distress was associated with more sleep disturbances ( b = 0.15, p < 0.001) and SRI ( b = 0.24, p < 0.001). Generational status was not associated with sleep, nor did it modify associations between COVID‐19 distress and sleep. Findings highlight the potential importance of developing interventions to reduce stress and sleep difficulties during the pandemic. Our results did not support the immigration paradox. Future studies are needed to better understand the role of generational status on sleep health across immigrant subgroups.

Introduction The COVID-19 pandemic has resulted in substantial changes in social interactions, work schedules, and socioeconomic factors that may negatively impact sleep onset, maintenance, and quality. The ongoing stress of the pandemic also may exacerbate existing racial/ethnic disparities in sleep health. In this study, we examined the effects of COVID-19 related distress on sleep-related impairment and sleep disturbances among trauma-exposed South Asian adults. Since a health advantage among foreign-born individuals has been previously noted in the literature (the “immigrant paradox”), we also assessed whether generational status (i.e., being born in the U.S. or not) moderated associations between COVID-19 related distress and sleep outcomes. Methods Participants were recruited through Amazon’s Mechanical Turk and completed online surveys on demographic information, the COVID-19 Stress Scale, The Life Events Checklist for DSM-5 (LEC-5), and PROMIS™ Sleep-Related Impairment and Sleep Disturbances Scale. The final sample included 316 South Asian adults residing in the U.S, who had been exposed to a traumatic event at some point in their lifetime. Most participants were male (55%) and U.S.-born citizens (64%), with an average age of 35.32 (SD = 9.52) years. Results Examination of t-scores for PROMIS™ sleep-related and sleep disturbances revealed that our sample endorsed slightly higher values than the general U.S. population. Greater COVID-19 distress was associated with more sleep disturbances (b = 0.09, p &lt; .001, sr2 = .04) and sleep-related impairment (b = 0.20, p &lt; .001, sr2 = .12). Generational status was not associated with sleep, nor did it modify associations between COVID-19 distress and sleep. Conclusion In our sample, we found that psychological distress triggered by the pandemic (e.g., fear of contamination, fear of the dangerousness of the virus, socioeconomic worries) was associated with greater sleep difficulties. Our findings highlight the importance of developing targeted interventions to cope with stress and sleep disturbances during the pandemic, particularly among vulnerable populations, such as those exposed to trauma. Our results did not support the immigration paradox: stress and sleep associations were similar regardless of generational status. Future studies are needed to better understand the role of generational status on sleep across different immigrant subgroups. Support (If Any)

Study Objectives: Habitual sleep duration and efficiency vary widely by age, gender, and racial/ethnic identity. Despite growing research on the importance of night-to-night, intraindividual 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. Methods: Eight international data sets of healthy sleepers (N = 2404; 26,121 total days of sleep data) were synthesized to examine age, gender, and racial/ethnic identity differences in sleep IIV measured via diaries, actigraphy, and electroencephalography. Sleep IIV estimates included the intraindividual standard deviation (iSD), root mean square of successive differences (RMSSD), coefficient of variation (CV), and a validated Bayesian Variability Model (BVM). Results: Sleep duration and efficiency varied widely from night-to-night within people (duration iSD: 67.04–85.80 minutes; duration RMSSD: 91.93–118.91 minutes; duration CV: 18.57–19.19%; duration BVM: 48.60–60.60 minutes; efficiency iSD: 5.18–6.46%, efficiency RMSSD: 7.01–8.44%; efficiency CV: 5.80–8.14%; efficiency BVM: 3.40–4.16%). Different metrics of IIV were strongly correlated for sleep duration (rs .58–.97) and sleep efficiency (rs .53–1.00). Younger adults had more IIV in diary and actigraphy sleep duration. Gender differences were inconsistent. White and non-Hispanic/Latinx adults had less IIV in sleep duration and efficiency compared to racial/ethnic minority groups. Conclusions: 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 characterize normative values of sleep IIV in healthy sleepers.