Difference In Total Sleep Time Research Articles

Sleep Duration Differences by Education from Middle to Older Adulthood: Does Employment Stratification Contribute to Gendered Leveling?

Sleep duration changes across the life course and differs by education in the United States. However, little research has examined whether educational differences in sleep duration change over age-or whether sleep duration trajectories over age differ by education. This study uses a life course approach to analyze American Time Use Survey data (N = 60,908), examining how educational differences in weekday sleep duration change from middle to older adulthood (ages 40-79). For men only, differences in total sleep time between individuals with less than a high school degree and those with more education converge in older adulthood. Results suggest that this leveling is explained by decreasing educational stratification in work hours as men enter older adulthood. Findings highlight the importance of employment for shaping gendered socioeconomic differences in sleep and demonstrate differences by education in how sleep duration changes over age, with possible implications for health disparities.

Follow-up of children with Down syndrome and sleep disordered breathing and the effects of treatment on actigraphically recorded sleep, quality of life, behaviour, and daytime functioning.

Children with Down syndrome are at increased risk of obstructive sleep disordered breathing, which has deleterious effects on daytime functioning. We aimed to examine the effects of treatment of sleep disordered breathing on sleep quality and daytime functioning in children with Down syndrome, and hypothesised that these would be improved. Thirty-four children completed a baseline study and a follow-up 2 years later. Measures at both time points included 7 days of actigraphy and parents completed a number of questionnaires assessing sleep, behaviour, daytime functioning, and quality of life. All children had overnight polysomnography at baseline; 15 children (44%) were treated. At baseline the treated group had more severe sleep disordered breathing compared with the untreated group: obstructive apneoa-hypopnoea index 29.3 ± 38.2 events/h versus 3.3 ± 5.2 events/h (p < 0.01). Actigraphy showed no significant differences in total sleep time, sleep efficiency, sleep schedules from baseline to follow up in either group. The sleep disturbance (p < 0.01) and total problems (p < 0.05) scales on the OSA-18 and the sleep disordered breathing subscale on the Paediatric Sleep Problem Survey Instrument (p < 0.01) improved in the treated children. There were no changes in any measure in the untreated children. Treatment of sleep disordered breathing improves symptoms, sleep disturbance and quality of life in children with Down syndrome, but has no demonstrable impact on actigraphic sleep measures or daytime behaviour or function. In contrast, children who were not treated, despite having less severe disease at baseline, had increased sleep disruption and no change in quality of life.

0283 Firefighters’ Sleep Changes After Switching Shift Schedules: A Longitudinal Study

Abstract Introduction In the past few years, fire departments in the US have been switching from 24 hours on / 48 hours off (24/48) shift schedule to the 48 hours on / 96 hours off (48/96) shift schedule to increase recruitment and reduce commute frequency for members living outside the jurisdiction. While firefighters at work may be able to rest and sleep when not otherwise busy, it is not a guarantee and concerns on health and safety understandably exist when subject to 48 hours on shift. Yet, it is unclear how switching schedules influence firefighters’ sleep. Therefore, the objective of this research is to assess sleep before and after firefighters transitioned from the 24/48 to the 48/96 shift schedule. Methods A pre-experimental, within-subjects, longitudinal sleep study was implemented with a Southcentral US fire department (n=24). Daily sleep included total sleep time (TST), sleep efficiency (SE), sleep latency (SL), and wake after sleep onset (WASO), and was assessed using wrist actigraphy and the Emergency Services Sleep Diary. Participants completed three, 18-day rounds of data collection: baseline assessment was conducted on the 24/48 and post assessments were conducted after three and six months following the transition to the 48/96. Results The results of separate one-way repeated measures ANOVA indicated a statistically significant difference in TST (F(2,46) = 4.58, p&amp;lt; 0.05), SE (F(2,46) = 7.97, p&amp;lt; 0.01), SL (F(2,46) = 6.88, p&amp;lt; 0.05), and WASO (F(2,46) = 5.58, p&amp;lt; 0.05) as firefighters transitioned schedules. Post-hoc analysis identified statistically significant pairs between the 24/48 and the three-month post assessment for each sleep parameter: TST (6.4h vs 6.8h), SL (85% vs 89%), SL (8.7min vs 4.9min), and WASO (58min vs 45min). Conclusion Firefighters reported an improvement in sleep three months after transitioning to the 48/96. The results suggest that improved sleep on the 48/96 may be related to consolidating work shifts, which reduces the frequency of experiencing advance sleep offset on commute days and allows a greater recovery period at home. While further research is needed to assess how health and performance outcomes are related to firefighter schedules, the findings suggest that the pattern of work and non-workshifts influences sleep. Support (if any)

0806 Treatment of sleep disordered breathing improves quality of life in children with Down syndrome

Abstract Introduction Children with Down syndrome (DS) are at increased risk of obstructive sleep disordered breathing (SDB), which is associated with sleep disruption affecting daytime functioning. We examined the effects of treatment of SDB on sleep and daytime functioning in children with DS. Methods Children with DS and SDB (n=34) completed a baseline and follow-up study which included 7 days of actigraphy in conjunction with a parental sleep diary. Parents also completed a number of questionnaires assessing sleep, behaviour, daytime functioning and quality of life (QOL). All children had overnight polysomnography (PSG) at baseline and 24 had PSG at follow-up. Results 15 children (44%) were treated. At baseline the treated group had more severe SDB at baseline compared to the untreated group: obstructive apnoea hypopnoea index (OAHI) 29.3 ± 38.2 events/h vs 3.3 ± 5.2 events/h (p&amp;lt; 0.01). Actigraphy showed no significant differences in total sleep time or sleep efficiency from baseline to follow up in either the treated or untreated group. Wake after sleep onset increased at follow-up in the untreated group (p&amp;lt; 0.01). The sleep disturbance (p&amp;lt; 0.01) and total problems (p&amp;lt; 0.05) scales on the OSA-18 and the SDB subscale on the Pediatric Sleep Problem Survey Instrument (p&amp;lt; 0.01) improved in the treated children. No changes were seen in any of the measures in the untreated children. Conclusion Treatment of SDB improves QOL, despite treatment having no demonstrable impacts on actigraphic sleep measures. In contrast despite having less severe SDB children who were untreated had no improvements in QOL and increased sleep disruption. Support (if any) Jerome Lejeune Foundation

Assessing sleep in children with Down syndrome: Comparison of parental sleep diaries, actigraphy and polysomnography

BackgroundThis study compared measurements of sleep and wake assessed with actigraphy, sleep diary and polysomnography in children with Down syndrome (DS) and also compared measures of actigraphic sleep recording in children with DS and typically developing (TD) children. MethodsChildren with DS aged 3–19 years (N = 44) referred for assessment of sleep disordered breathing (SDB) underwent overnight polysomnography, together with 1 week of actigraphy with sleep diary. Actigraphy data from the children with DS were compared with data collected from TD children, matched for age and sex. Results22 children (50%) with DS completed >3 consecutive nights of actigraphy with a matched sleep diary. There were no differences between bedtimes, wake times or time in bed on weeknights, weekends or over 7 nights between actigraphy and sleep diary. Total sleep time was over estimated by the sleep diary by almost 2 h and the number of night awakenings under-reported. Compared to matched TD children (N = 22), there was no difference in total sleep time, however children with DS fell asleep more quickly (p < 0.001), had more awakenings (p = 0.001) and more time awake after sleep onset (p = 0.007). Children with DS exhibited less variability in both bedtimes and wake times, and fewer had >1 h sleep schedule variability. ConclusionsParental sleep diaries over-estimate total sleep time but accurately report bed and wake times compared to actigraphy in children with DS. Children with DS have more regular sleep patterns than TD children of the same age, which is important for optimising daytime functioning. The reasons behind this warrant further investigation.

The Effects of Long-term Social Distancing on Sleep and Mood in Adolescents During the COVID-19 Pandemic

Background: School timings could influence teens' sleeping patterns by interrupting their sleep or the timing of light can shift their biological clock. The COVID-19 pandemic has altered teens’ sleeping schedule making it important to analyze the effects of long-term social distancing on adolescents’ sleep and mood. Objectives: This study analyzes the effects of long-term social distancing, due to the COVID-19 pandemic, on their sleeping patterns and mood. Methods: In this cohort study, data from the 2018 – 2020 Korea Youth Risk Behavior Web-based Survey (KYRBS) were used to compare teens’ sleep patterns in 2020 with those in 2018 – 2019. The primary outcomes of this study were the sleep duration and sleep time of adolescents throughout the week, between 2018 and 2019, and in 2020. The secondary outcomes were the teens’ mood, health perception, and sleep satisfaction, including differences in total sleep time and sleep discrepancies between weekends and weekdays. Results: Around 58 – 63 thousand students were surveyed each year, and the participation rate was 94.9 – 95.6%. After exclusion, 132,839 teens participated in the survey. From 2018–2020, the height and body weight of the participants did not change. After adjusting for participants’ sex and school year, it was found that more teens felt happy, fewer teens experienced sadness and desperation, and fewer teens had suicidal thoughts in 2020, compared with the previous two years. They also slept 10 minutes later (9.743 (95% confidence interval 7.954 - 11.530)), with wake-up times of 3 – 5 minutes later on weekdays (4.684 (3.449 - 5.919)). On weekends during social distancing, they slept 16 minutes later (15.721 (14.077 - 17.366)), with wake-up times of 12 minutes later (12.309 (10.393 - 14.225)). Although they slept five minutes less on weekdays (-5.059 (-6.817 to -3.301)) and three minutes less on weekends (-3.413 (-5.419 to -1.407)), their overall sleep satisfaction increased, and differences in sleep duration between weekdays and weekends decreased in 2020. Conclusions: During social distancing, the mood and sleep efficiency of teens improved. In the future, once the COVID-19 pandemic subsides, online classes can be included in the curriculum of school systems to ensure healthy sleep patterns in teenagers.

COMPARISON OF SLEEP PARAMETERS FROM WRIST-WORN ACCELEROMETERS IN OLDER ADULTS

Abstract Researchers often prefer different accelerometers for measurement of sleep and physical activity (PA) in older adults, but wearing multiple accelerometers increases costs and participant burden. We tested the hypothesis that the Actiwatch-2, commonly used to measure sleep, and the ActiGraph GT9X Link, commonly used to measure PA, yield comparable sleep parameters among 331 participants (aged 71+/-14 years, 50.5% women) who wore them simultaneously for 7+/-1.6 nights in the BLSA. Compared to the Actiwatch-2, the ActiGraph estimated 50% greater wake after sleep onset, 89% longer wake bout length, 18% lower sleep fragmentation index (SFI), 5% lower total sleep time (TST) and 5% higher sleep efficiency. Yet, despite yielding different absolute values of TST and SFI, the devices generated similar between-person (relative) differences in TST and SFI. These devices may only be interchangeable for measurement of some relative sleep parameters in older adults. Studies with both devices and gold-standard polysomnography are needed.

O037 Understanding ventilatory control in children with Prader-Willi syndrome

Abstract Background Children with Prader-Willi syndrome (PWS) are at risk of both central and obstructive sleep apnoea (OSA), and have abnormal respiratory control during wakefulness. Many children with PWS are treated with growth hormone (GH) however, GH has been associated with the development of OSA. In this pilot study, we aimed to determine whether sleep and respiratory control (i.e. loop gain, LG) characteristics were altered by GH in children with PWS. Methods Pre- and post-GH polysomnographic data in children (aged 0-18 years) were retrospectively collected. LG was quantified in periods of NREM sleep by fitting a model of ventilatory control to the respiratory pattern following spontaneous sighs. Results Results (n=15, range 5-134 months, 46.7%F) were compared pre- and post-GH. No significant differences in total sleep time (474 [447, 498] vs 475 [451, 495.5]; p=0.81), percentage time in NREM and REM sleep, the obstructive apnoea-hypopnoea (OAHI) index (0.0 [0.0, 0.4] vs 0.3 [0.0, 0.7]; p=0.15) or the central apnoea-hypopnoea index (CAHI) (3.0 [0.7, 6.3] vs 2.8 [1.4, 4.6]; p=0.63) were found however, 1 child developed OSA. GH had no impact on LG (0.4 ± 0.1 vs 0.4 ± 0.1; p=0.99) and the change in OAHI/CAHI showed no correlation with the change in LG. Conclusions In this small cohort of children, the administration of GH had no impact on sleep and respiratory characteristics (including LG). A larger sample size maybe required to gain a more comprehensive understanding of the impacts of GH on ventilatory control in children with PWS.

P054 Effects of treatment of sleep disordered breathing on actigraphic sleep measures and daytime functioning in children with Down syndrome

Abstract Background Children with Down syndrome (DS) are at increased risk of obstructive sleep disordered breathing (SDB), which is associated with sleep disruption affecting daytime functioning. We examined the effects of treatment of SDB on sleep and daytime functioning in children with DS. Methods Children with DS and SDB (n=34) completed a baseline and follow-up study which included 7 days of actigraphy in conjunction with a parental sleep diary. Parents also completed a number of questionnaires assessing sleep, behaviour, daytime functioning and quality of life (QOL). All children had overnight polysomnography (PSG) at baseline and 24 had PSG at follow-up. Results 15 children (44%) were treated. At baseline the treated group had more severe SDB at baseline compared to the untreated group: obstructive apnoea hypopnoea index (OAHI) 29.3 ± 38.2 events/h vs 3.3 ± 5.2 events/h (p&amp;lt;0.01). Actigraphy showed no significant differences in total sleep time or sleep efficiency from baseline to follow up in either the treated or untreated group. Wake after sleep onset increased at follow-up in the untreated group (p&amp;lt;0.01). The sleep disturbance (p&amp;lt;0.01) and total problems (p&amp;lt;0.05) scales on the OSA-18 and the SDB subscale on the Pediatric Sleep Problem Survey Instrument (p&amp;lt;0.01) improved in the treated children. No changes were seen in any of the measures in the untreated children. Conclusions Treatment of SDB improves QOL, despite treatment having no demonstrable impacts on actigraphic sleep measures. In contrast despite having less severe SDB children who were untreated had no improvements in QOL and increased sleep disruption.

O066 The Impact of Work Break Characteristics on Sleep Duration in Heavy Vehicle Drivers

Abstract Introduction Heavy vehicle drivers (HVDs) frequently experience reduced sleep due to travelling long distances under non-standard work hours. Short sleep in HVDs can increase risk of motor vehicle crashes and falling asleep while driving. This study sought to examine the influence of break duration between shifts, break onset time, and prior shift duration on HVDs’ total sleep time (TST) between consecutive work shifts, and the interaction between break duration and break onset time. Methods Twenty-seven HVDs’ sleep and shift work were monitored for up to nine weeks through actigraphy, sleep diaries, and work diaries. Differences in TST between consecutive shifts and days off were assessed. Linear mixed models and pairwise comparisons evaluated the impact of break duration, break onset time, and prior shift duration on TST between shifts. Results TST was significantly lower between consecutive shifts (M=6.38-hours) compared to days off (M=7.63-hours), p&amp;lt;.001. Longer break durations were associated with more TST, p&amp;lt;.001. Break durations up to 7-, 9-, and 11-hours resulted in, on average, 4.76-, 5.66-, and 6.41-hours of sleep, respectively. Breaks starting between 00:01-08:00h led to shorter TST compared to breaks starting between 16:01-20:00h, p&amp;lt;.05. Prior shift duration and the interaction between break duration and break onset time were not associated with TST. Discussion HVDs’ TST between workdays are independently impacted by break duration and break onset time. Break durations between 7-11-hours, reflecting Australian and European break guidelines, result in insufficient sleep. Work regulations must evaluate appropriate break durations and break onset times to allow adequate sleep in HVDs.

P042 Actigraphy-derived sleep characteristics of healthy children who benefit the most from a sleep extension protocol

Abstract Introduction Although experimental manipulation of sleep can extend children’s sleep via earlier bedtimes, this is not always possible. We aimed to determine true sleep gains made with a one hour earlier bedtime, and which actigraphy variables at baseline predicted the best gains. Methods Secondary analysis within a randomised crossover trial (99 children; 49.5% female; mean age=10.3 years, range 8-12 years). Each child underwent one week of sleep restriction and extension in a random order (1h later or earlier bedtime respectively) separated by a one-week washout. Sleep data comparing baseline and extension weeks were analysed using linear or logistic regression, controlling for randomised order. Results The mean (SD) difference in total sleep time (TST) with sleep extension was 14.3 (44.1) min/night. Thirty-three percent extended their sleep by at least 30 min/night. At baseline, having lower sleep quantity (TST) and quality (efficiency, WASO, waking frequency) significantly predicted more sleep gain. For each 1 h lower TST at baseline, 29.7 min (95% CI 19.4, 40.1) more sleep was gained. At baseline, a TST below 8 h 49 min was the optimal cut-point to predict whether children could extend their sleep by at least 30 min/night (found in 40% of children). Adjusting for relevant demographics and sleep hygiene made little difference. Conclusion Children who slept less than 8 h 49 min/night obtained the most sleep gain from a 1 hour earlier bedtime maintained over a week. Maintenance over the longer term is unknown. Findings have implications for understanding the sleep requirements of children.

The impact of break duration, time of break onset, and prior shift duration on the amount of sleep between shifts in heavy vehicle drivers.

This study aimed to examine the impact of break duration between consecutive shifts, time of break onset, and prior shift duration on total sleep time (TST) between shifts in heavy vehicle drivers (HVDs), and to assess the interaction between break duration and time of break onset. The sleep (actigraphy and sleep diaries) and work shifts (work diaries) of 27 HVDs were monitored during their usual work schedule for up to 9 weeks. Differences in TST between consecutive shifts and days off were assessed. Linear mixed models (followed by pairwise comparisons) assessed whether break duration, prior shift duration, time of break onset, and the interaction between break duration and break onset were related to TST between shifts. Investigators found TST between consecutive shifts (mean [SD] 6.38[1.38]h) was significantly less than on days off (mean [SD] 7.63[1.93]h; p < 0.001). Breaks starting between 12:01 and 8:00 a.m. led to shorter sleep (p < 0.05) compared to breaks starting between 4:01 and 8:00 p.m. Break durations up to 7, 9, and 11 h (Australian and European minimum break durations) resulted in a mean (SD) of 4.76(1.06), 5.66(0.77), and 6.41(1.06)h of sleep, respectively. The impact of shift duration prior to the break and the interaction between break duration and time of break were not significant. HVDs' sleep between workdays is influenced independently by break duration and time of break onset. This naturalistic study provides evidence that current break regulations prevent sufficient sleep duration in this industry. Work regulations should evaluate appropriate break durations and break onset times to allow longer sleep opportunities for HVDs.

Validation of mandibular movements' analysis to measure sleep in adults with sleep complaints by comparison with actigraphy and polysomnography.

ObjectiveIn adults with sleep complaints, we assessed the software of automatic analysis of mandibular movements to identify sleep and wake states by confrontation with the polysomnography (PSG) and the actigraphy (ACTG).Material and MethodsSimultaneous and synchronized in-lab PSG, ACTG, and JAWAC were carried out in 100 patients with a sleep complaint. Epoch by epoch analysis was realized to assess the ability to sleep-wake distinction. Sleep parameters as measured by the three devices were compared. These included three regularly reported parameters: total sleep time (TST), sleep onset latency (SOL), and wake after sleep onset (WASO). Also, two supplementary parameters, wake during sleep period (WDSP) and latency to arising (LTA) were added to measure separately the quiet wakefulness states.ResultsThe epoch by epoch analysis showed that the JAWAC, as compared to ACTG, classified sleep and wake states with greater specificity, while the overall accuracy and sensitivity of the two devices were comparable. The sleep parameters analysis showed that for the JAWAC estimates, the differences in TST, SOL, and LTA values were not statistically significant. However, WDSP and subsequently WASO were slightly underestimated. In contrast, the dissimilarities between ACTG estimates and PSG measurements of all the above sleep parameters were statistically significant; TST was overestimated whilst SOL, LTA, WDSP, and WASO were underestimated.ConclusionThis study indicated that, besides its ability to reliably estimate TST, the JAWAC based on mandibular movements’ analysis was able, in adults with sleep complaints, to overcome the important problem of the recognition of the state of quiet wakefulness.

Analysis of Daily Sleep Diary Measures From Multilayer Extended-Release Methylphenidate (PRC-063) Studies in Children and Adults With ADHD

Objective: To compare the effect of a once-daily extended-release methylphenidate formulation (PRC-063) versus placebo on sleep, measured via daily electronic diary in two clinical trials in pediatric (6–12 years) and adult (≥18 years) patients with attention deficit hyperactivity disorder (ADHD). Method: A diary was completed by adult patients or parents/caregivers of pediatric patients during two randomized, double-blind, placebo-controlled laboratory classroom studies. Following dose optimization of PRC-063, patients were randomized to 1 week of double-blind treatment with PRC-063 or placebo before attending a full-day laboratory classroom session. Results: In the studies, 148 pediatric patients and 239 adult patients were randomized to either PRC-063 or placebo. When compared with the diaries of placebo patients, the sleep diaries in both pediatric and adult patients showed no statistical difference in total sleep time, efficiency, or latency. Conclusion: PRC-063 did not impact subjective measures of sleep versus placebo in pediatric and adult patients with ADHD.

0474 Three-arm randomised controlled trial of Cognitive Behavioural Therapy for Insomnia, a responsive bassinet, and sleep hygiene for preventing postpartum insomnia: Preliminary findings on maternal insomnia and sleep outcomes (Study for Mother-Infant Sleep)

Abstract Introduction Insomnia symptoms are common during the perinatal period and are linked to adverse parent/infant outcomes. This single-blind 3-arm randomised controlled trial examined how two interventions targeting different mechanisms prevent postpartum insomnia compared to sleep hygiene control. Trial registration: ACTRN12619001166167. Methods Participants were nulliparous females 26-32 weeks gestation with self-reported insomnia symptoms (Insomnia Severity Index [ISI] scores ≥ 8). Participants were randomized 1:1:1 to: (a) a responsive bassinet designed to support infant sleep until 6 months postpartum (RB), (b) therapist-assisted cognitive behavioural therapy for insomnia (CBT-I) delivered during pregnancy and postpartum, or (c) a sleep hygiene booklet (control condition; CTRL). Outcomes were assessed at baseline (T1), 35-36 weeks gestation (T2), and 2, 6, and 12 months postpartum (T3-T5). The primary outcome is ISI scores averaged T3-T5. Secondary outcomes are PROMIS Sleep Disturbance (SDI), Sleep-Related Impairment (SRI), and self-report total sleep time (TST). We report preliminary results on T1-T4 as T5 is ongoing. Multiple regression analyses controlling for baseline outcomes examined group differences at post-baseline timepoints. Results 127 participants were randomised (age M±SD=32.62±3.49; RB = 44, CBT-I = 42, CTRL = 41), and 118 (92.9%) completed T4. Compared to CTRL, CBT-I had lower ISI, SDI, and SRI at T2, T3, and T4 (all p&amp;lt;.05 except p=.07 and .06 for ISI at T3 and T4; Cohen’s d ranges 0.39-0.99); differences in TST were non-significant at all timepoints (all p&amp;gt;.25). The RB condition had significantly longer TST at T4 (40.10 min longer, p=.008, d=.63) compared to CTRL, but these two conditions did not differ significantly on any other measures across all timepoints (p&amp;gt;.22). Conclusion Preliminary findings suggest CBT-I was efficacious in preventing insomnia symptoms and reducing sleep disturbance and sleep-related impairment, but did not increase maternal sleep duration postpartum. Conversely, a responsive bassinet designed to support infant sleep meaningfully increased maternal sleep duration at 6 months postpartum but did not prevent insomnia symptoms. These initial findings suggest that perinatal sleep complaints are a multifactorial problem that likely require multi-component interventions targeting different causes and mechanisms. Support (If Any) National Health and Medical Research Council, Department of Education and Training.

0597 The Relationship Between Sleep Quality and Functional Outcomes Following Acute Stroke and Inpatient Rehabilitation

Abstract Introduction There is mounting evidence that sleep plays an important role in the rehabilitation and recovery process following acute stroke. Following acute care, many patients with stroke are admitted to inpatient rehabilitation facilities (IRFs), where they undergo intensive, interdisciplinary therapy to recover or relearn functional skills to minimize long-term disability. The role and impact of sleep in this early stage of stroke rehabilitation, however, is poorly understood. The purpose of this study is to investigate the relationship between sleep quality and clinical outcomes in the IRF setting following acute stroke. Methods Patients wore a collection of wearable sensors to measure sleep and wake throughout their IRF stay. Linear mixed-effect models (LMEMs) were built to determine the relationship between functional outcomes and sleep quality. Independent variables were total sleep time (TST) and sleep efficiency (SE) derived from wearable sensors, calculated between two clinical measures. Dependent variables included scores from repeated measures of the 6-Minute Walk Test (6MWT), 10-Meter Walk Test (10MWT), Berg Balance Scale (BBS), and Action Research Arm Test (ARAT). Covariates included demographics such as age and stroke type. Results Fifty-three individuals with stroke (age: 58.26±15.57 years; BMI: 28.27±6.16 kg/m2) consented to participate during their IRF program within 7 days of admission. All individuals were recruited from a single-site IRF between July 2020 and August 2021. The average length of stay was 17.85±6.99 days. There were no significant differences in TST between the first three nights and the last three nights (5.1±1.9 hours vs. 5.2±2.0 hours) or SE (67.8±17.7% vs. 69.0±17.8%). The greater standard deviation of TST was associated with lower 6MWT scores (R2=0.77, beta=−0.48, p=0.06), while the greater standard deviation of SE was associated with lower 10MWT scores (R2=0.80, beta=−0.20, p=0.18). Conclusion Our preliminary findings indicate that greater variability in TST and SE are associated with walking endurance and mobility recovery. Future analyses will investigate additional measures of sleep and activity in IRF settings and their relationship with patient outcomes. This work can inform novel sleep interventions to optimize post-stroke recovery. Support (If Any) This work is supported by the Eunice Kennedy Shriver National Institute of Child Health &amp; Human Development (NIH R01HD097786-01A1).

0501 Sleep pattern changes two years after participating in the Makos sleep study: The effect of extending total sleep time and weighted blankets on teenage swimmers performance

Abstract Introduction The initial Makos study was conducted in 2019, studying the effect of extending total sleep time and the use of weighted blankets (ETST+WB) on teenage swimmers’ performance. In it, we found a significant improvement of 100-free style race time in teenage swimmers after ETST+WB. The aim of the current follow-up study is to evaluate the sleep pattern of the same swimmers after 2 years. Methods Using an open-label prospective approach, the study investigated swimmer’s event time changes, total sleep time, daytime sleepiness, and other sleep measures after 2 years of the initial changes during the first study. 8 healthy swimmers on the Makos swim team filled follow-up questionnaires and participated in a 100-yard freestyle race. Descriptive statistics, frequency distributions, and correlation using SPSS 14. Results Eight (6F; 2M) of the initial nine seasonal teen swimmers participated (age 13-17). Four swimmers reported headaches and one reported sore throat in the morning. Three (37.5%) reported feeling sleepy during the day and 3 reported falling asleep when riding in a car. Two reported leg movements during the night. In two years after the initial study, 100-free race time significantly improved (65.01*5.38 vs 59.32*5.43 p=0.003), but the positive effect of ETST+WB on recorded sleep time was lost and returned to baseline. There was a clear trend, but no significant difference in total sleep time among the 3 groups: (initial 8:45 *0:32; after ETST+WB 9:17*0:32; after 2 years 8:08*0:30). Conclusion The improvement of total sleep time with weighted blankets and encouragement during the initial study correlated with improvement of 100 free race time in seasonal teen swimmers. This improvement in total sleep time was lost and returned back to baseline after 2 years follow up. Support (If Any) The authors report no financial relationship with any company whose products are mentioned in this manuscript, or with companies of competing products. Participants will be able to keep SKY Grand activity trackers at the end of their participation.

0720 Accuracy of WatchPat Portable Sleep Monitoring and Sleep Assessment in Patients with Atrial Fibrillation

Abstract Introduction Obstructive sleep apnea(OSA) is an established risk factor for atrial fibrillation(AF), necessitating early diagnosis and management. Home-based sleep-monitoring technology has become a mainstream diagnostic modality. Peripheral arterial tonometry (PAT) device is increasingly being used to screen for OSA in patients with AF. Our study aimed to examine the accuracy of Watch-PAT (WP) in OSA evaluation, and night-to-night variability of sleep characteristics as measured by WP when used during consecutive night sleep studies. Methods Patients with history of AF undergoing clinically indicated PSG were prospectively enrolled and had concurrent WP while undergoing PSG. Patients then were studied again using WP over two consecutive days at home. We compared agreement of OSA severity(defined as no OSA[AHI (apnea hypopnea index)&amp;lt;5], mild OSA[15&amp;gt;AHI³5], moderate OSA[30&amp;gt;AHI³15], severe OSA[AHI&amp;gt;30]) and total sleep time(TST) using Cohen’s Kappa(K) for categorical and Bland-Altman plots for continuous variables. To further characterize PSG versus WP, the cohort was stratified into paroxysmal versus persistent AF types. 1A/1B hypopnea scoring criteria was defined as per AASM. Results Our cohort included 24 patients with AF(80% male, mean age 68y). Most patients had clinically defined OSA(AHI³5). Patients with persistent AF had more severe OSA than those with paroxysmal AF (severe OSA present in 60% vs. 29%). Comparison of PSG to concurrently conducted WP in the lab showed substantial agreement in OSA severity by both 1A(K=0.623) and 1B(0.706) criteria. Percent difference in TST between PSG versus WP in the paroxysmal AF versus persistent groups was not statistically significant(p=0.387). Comparing two consecutive at-home WP tests showed substantial agreement in OSA severity measures(1A=0.872,1B=0.889). Bland-Altman plots for TST and sleep architecture showed ³95% of residuals within 2 standard-deviations, suggesting intertester agreement. Confidence intervals were broad in these plots reflecting our small sample size. Conclusion Our findings demonstrate that WP is a reasonable alternative to PSG, particularly if using the 1B criteria to diagnose OSA. Additionally, our results show that persistent versus paroxysmal AF does not seem to affect the results of WP tests. Night to night variability of OSA measures and TST was small. Future studies should verify the results of our study in a larger cohort. Support (If Any)

0140 Operationalizing Sleep for the Military: Advancing an Infrastructure for Fatigue Risk Management with Wearable Technology

Abstract Introduction A recent investigation on fatigue within United States (US) Naval Surface Force by the Government Accountability Office recommended that the US Navy incorporate methods to empirically monitor and manage fatigue-related threats. In response, a feasibility effort was undertaken to assess two commercial wearable devices previously evaluated against polysomnography by our group for potential use within a novel fatigue monitoring system onboard US warships. Methods 501 Sailors from three warships (415 men, 85 women, 1 response missing; 29.1±7.4 years, mean±SD) were included in analyses. During multi-day missions at sea, participants were instructed to continuously wear a wrist-worn Fatigue Science Readiband and an Oura Ring. Participants met with the research team daily to sync wearable devices and complete self-ratings of sleep and fatigue on a tablet. While returning to port, participants completed a user experience questionnaire that included 5-point scales for device comfort and interference with daily activities (larger values indicate greater comfort or interference). Results There were no overall differences in total sleep time (TST) and sleep efficiency (SE) between devices (TST: Ring=352.23±87.1, Readiband=353.89±97.79; p=0.45, d=-0.01; SE: Ring=84.59±7.08, Readiband=84.20±10.24; p=0.06, d=0.04). There were 9 days for TST and 4 days for SE (of 66 total days) that resulted in effect sizes &amp;gt;0.50 between devices (for &amp;gt;0.20: TST, 39/66; SE, 29/66). Preliminary analyses between TST and self-reported exhaustion and inability to function suggest predictive relationships with the wearables (Ring: r=-0.20; Readiband: r=-0.21), with no relationship with SE across devices (both r&amp;lt;0.01). Average comfort ratings for Ring (3.74) exceeded Readiband (3.59), but this difference was small (p=0.04, d=0.12). Interference with daily activities was also similar between devices (Ring=2.10, Readiband=2.20; p=0.14, d=0.08). Conclusion Both commercial wearables performed similarly for their TST and SE assessments, and TST was associated with self-rated fatigue within this operational environment. While the ring form factor was selected more for comfort than the wrist form factor, the difference was small. Collectively, findings indicate that both devices show promise for operational use within fatigue monitoring systems. Further testing is being conducted to better understand the strengths and limitations of wearable devices for monitoring sleep in warship environments. Support (If Any) Military Operational Medicine Research Program

0521 Prevalence and Characteristics of Sleep Disordered Breathing in 12-24 Month Old Children: A Single Center Study

Abstract Introduction To evaluate the prevalence and characteristics of obstructive sleep apnea (OSA) in children with ages between 12 to 24 months. Methods This was a single center, retrospective study that included children with ages 12-24 months who were evaluated for suspected sleep disordered breathing and underwent a full overnight polysomnography in an academic sleep disorders center over a period of 7 years. An apnea hypopnea index (AHI) &amp;gt;1 was used to define OSA, &amp;gt;5 was used to define moderate OSA, and &amp;gt;10 was used to define severe OSA. Results A total of 232 children with ages between 12-24 months were included in this study. The majority (66.4%) were noted to be males, and 56.9% were Caucasian. Snoring (90.1%) and witnessed apnea (53.3%) were the most common presenting symptoms for sleep evaluation. History of prematurity (18.2%) and gastroesophageal reflux (20.2%) were common co-morbidities. OSA was diagnosed in about 79% of the children and it was categorized as mild in 53.5%, moderate in 16.4 % and severe in 30.1%, respectively. There were no statistically significant differences in total sleep time, sleep efficiency, or the stages among these groups. However, statistical significant differences among the groups were noted in median REM% (Q1-Q3) (normal 19.3 (15-22.2) vs. mild 22.2 (18-26.6) vs. moderate 23.1(16-28) vs. severe 21(15-24.6) p=0.013), median REM AHI (normal 1.6 (1-2.8) vs. mild 7.5 (5-10.8) vs. moderate19.4 (12-23.6) vs. severe 51.2 (37-73.4) p&amp;lt;0.001), median OAHI (normal 0.3 (0-0.5) vs. mild 1.1 (1-2.6) vs. moderate 5.5 (4-7.5) vs. severe 20.7 (13-31.9) p&amp;lt;0.001), median supine AHI (normal-0.3 (0.0.6) vs. mild 1.7 (1-3.4) vs. moderate 6.3 (3-8.1) vs. severe 24.3(12-40.4) p&amp;lt;0.001), median SaO2 nadir (normal 94 (90-96) vs. mild 89 (84-91) vs. moderate 86.5 (82-91) vs. severe 80 (73-84) p&amp;lt;0.001), median arousal index (normal 8.9 (7-11.8) vs. mild 11.3 (9-13.5) vs. moderate 13.2 (11-18.6) vs. severe 16.8 (14-23.6) p&amp;lt;0.0001). Surgical treatment was performed in 98 children (53.5% of the children diagnosed with OSA) of which 76 surgeries were adenotonsillectomy. Conclusion In children with ages 12-24 months with suspected sleep disordered breathing, OSA was diagnosed in 79% with moderate to severe OSA in 46.5%. Support (If Any)