Who meets national early childhood sleep guidelines in Aotearoa New Zealand? A cross-sectional and longitudinal analysis

Study Objectives To investigate the proportion of children in Aotearoa New Zealand (NZ) who do or do not meet sleep duration and sleep quality guidelines at 24 and 45 months of age and associated sociodemographic factors. Methods Participants were children (n=6,490) from the Growing Up in New Zealand longitudinal study of child development with sleep data available at 24 and/or 45 months of age (48.2% girls, 51.8% boys; 22.4% Māori [the Indigenous people of NZ], 12.9% Pacific, 13.4% Asian, 45.2% European/Other). Relationships between sociodemographic factors and maternally-reported child sleep duration (across 24 hours) and night wakings were investigated cross-sectionally and longitudinally. Estimates of children in NZ meeting sleep guidelines were calculated using a range of analytical techniques including Bayesian linear regression, negative binomial multiple regression, and growth curve models. Results In NZ, 29.8% and 19.5% of children were estimated to have a high probability of not meeting sleep duration guidelines and 15.4% and 8.3% were estimated to have a high probability of not meeting night waking guidelines at 24 and 45 months respectively, after controlling for multiple sociodemographic variables. Factors associated cross-sectionally with children’s sleep included ethnicity, socioeconomic deprivation, material standard of living, rurality and heavy traffic, and longitudinal sleep trajectories differed by gender, ethnicity and socioeconomic deprivation. Conclusions A considerable proportion of young children in NZ have a high probability of not meeting sleep guidelines but this declines across the ages of 24 and 45 months. Sleep health inequities exist as early as 24 months of age in NZ.

Validation of Somno-Art Software, a novel approach of sleep staging, compared with polysomnography in disturbed sleep profiles

Integrated analysis of heart rate (electrocardiogram [ECG]) and body movements (actimetry) during sleep in healthy subjects has previously been shown to generate similar evaluation of sleep architecture and continuity with Somno-Art Software compared to polysomnography (PSG), the gold standard. However, the performance of this new approach of sleep staging has not yet been evaluated on patients with disturbed sleep. Sleep staging from 458 sleep recordings from multiple studies comprising healthy and patient population (obstructive sleep apnea [OSA], insomnia, major depressive disorder [MDD]) was obtained from PSG visual scoring using the American Academy of Sleep Medicine (AASM) rules and from Somno-Art Software analysis on synchronized ECG and actimetry. Inter-rater reliability, evaluated with 95% absolute agreement intra-class correlation coefficient, was rated as "excellent" (ICCAAAvg95% ≥0.75) or "good" (ICCAAAvg95% ≥0.60) for all sleep parameters assessed, except NREM and N3 sleep in healthy participants (ICCAAAvg95% =0.43, ICCAAAvg95% =0.56) and N3 sleep in OSA patients (ICCAAAvg95% =0.59) rated as "fair" inter-rater reliability. Overall sensitivity, specificity, accuracy and Cohen's kappa coefficient of agreement (κ)on the entire sample were respectively of 93.3%, 69.5%, 87.8% and 0.65 for wake/sleep classification and accuracy and κ were of 68.5% and 0.55 for W/N1+N2/N3/REM classification. These performances were similar in healthy and patient population. The present results suggest that Somno-Art can be a valid sleep-staging tool in both healthy subjects and patients with OSA, insomnia or MDD. It could complement existing non-attended techniques measuring sleep-related breathing pattern or be a useful alternative to laboratory-based PSG when this latter is not available.

Genetic and Environmental Influences on Sleep-Wake Behaviours in Adolescence

Study Objectives To investigate the influence of genetic and environmental factors on sleep-wake behaviours across adolescence. Methods Four hundred and ninety-five participants (aged 9 to 17; 55% females), including 93 monozygotic (MZ) and 117 dizygotic (DZ) twin pairs, and 75 unmatched twins, wore an accelerometry device and completed a sleep diary for two weeks. Results Individual differences in sleep onset, wake time, and sleep midpoint were influenced by both additive genetic (44-50% of total variance) and shared environmental (31-42%) factors, with a predominant genetic influence for sleep duration (62%) and restorative sleep (43%). When stratified into younger (aged 9-14) and older (aged 16-17) subsamples, genetic sources were more prominent in older adolescents. The moderate correlation between sleep duration and midpoint (rP = -.43, rG = .54) was attributable to a common genetic source. Sleep-wake behaviours on school and non-school nights were correlated (rP = .44-.72) and influenced by the same genetic and shared environmental factors. Genetic sources specific to night-type were also identified, for all behaviours except restorative sleep. Conclusions There were strong genetic influences on sleep-wake phenotypes, particularly on sleep timing, in adolescence. Moreover, there may be common genetic influences underlying both sleep and circadian rhythms. The differences in sleep-wake behaviours on school and non-school nights could be attributable to genetic factors involved in reactivity to environmental context.

Chronotype as self-regulation: morning preference is associated with better working memory strategy independent of sleep

Study objectives We set out to examine how chronotype (diurnal preference) is connected to ability to function in natural conditions where individuals cannot choose their sleep schedule. We conducted a cross-sectional study in military conscript service to test the hypothesis that sleep deprivation mediates the adverse effects of chronotype on cognitive functioning. We also examined the effects of time of day. Methods 140 participants (ages 18-24 years) completed an online survey, including the Morningness-Eveningness Questionnaire (MEQ) and a Cambridge Neuropsychological Test Automated Battery (CANTAB). Most (n=106) underwent an actigraphy recording. After bivariate analyses, we created a mediation model (self-reported sleepiness and sleep deprivation mediating effect of chronotype on cognition) and a moderation model (synchrony between most alert time and testing time). Results Reaction times in inhibition task correlated negatively with sleep efficiency and positively with sleep latency in actigraphy. There was no relation to ability to inhibit responses. More significantly, spatial working memory performance (especially strategicness of performance) correlated positively with morning preference and negatively with sleep deprivation before service. Synchrony with most alert time of the day did not moderate these connections. No other cognitive task correlated with morningness or sleep variables. Conclusions In line with previous research, inhibitory control is maintained after insufficient sleep but with a tradeoff of slower performance. The connection between morning preference and working memory strategy is a novel finding. We suggest that diurnal preference could be seen as an adaptive strategy, as morningness has consistently been associated with better academic and health outcomes.

Diagnosed or prescribed only? A national analysis of initial evaluation and management of insomnia among older adult Medicare beneficiaries

Study Objectives To describe initial insomnia-related encounters among a national sample of Medicare beneficiaries, and to identify older adults at risk for potentially inappropriate prescription insomnia medication usage. Methods Our data source was a random 5% sample of Medicare administrative claims data (2006-2013). Insomnia was operationalized as International Classification of Disease, Ninth Revision, Clinical Modification diagnostic codes. Insomnia medications included FDA-approved insomnia-related medication classes and drugs. Logistic regression was employed to identify predictors of being “prescribed only” (i.e., being prescribed an insomnia medication without a corresponding insomnia diagnosis). Results A total of N=60,362 beneficiaries received either an insomnia diagnosis or a prescription for an insomnia medication as their first sleep-related encounter during the study period. Of these, 55.1% (n=33,245) were prescribed only, whereas 44.9% (n=27,117) received a concurrent insomnia diagnosis. In a fully adjusted regression model, younger age (odds ratio (OR) 0.98; 95% confidence interval (CI) 0.98, 0.99), male sex (OR 1.15; 95% CI 1.11, 1.20), and several comorbid conditions (i.e., dementia [OR 1.21; 95% CI 1.15, 1.27] and anemia [OR 1.17; 95% CI 1.13, 1.22]) were positively associated with being prescribed only. Conversely, black individuals (OR 0.83; 95% CI 0.78, 0.89) and those of “other” race (OR 0.89; 95% CI 0.84, 0.94) were less likely to be prescribed only. Individuals who received care from a board-certified sleep medicine provider (BCSMP) were less likely to be prescribed only (OR 0.27; 95% CI 0.16, 0.46). Conclusions Fewer than half of Medicare beneficiaries prescribed insomnia medications ever received a formal sleep-related diagnosis.

O003 The impact of wind farm noise in a laboratory setting on objective and subjective sleep efficiency

Introduction Well-controlled studies of wind farm noise (WFN) on sleep are lacking despite complaints and known effects of other noise types on sleep. This laboratory-based study investigated the impact of continuous full-night WFN exposure replicated from field recordings on polysomnography-measured (objective) and sleep diary-determined (subjective) sleep efficiency compared to a quiet control night. Methods Based on residential location and self-report data, 50 participants were categorised into three groups (14 living <10km from a wind farm and self-reporting sleep disturbance; 19 living <10km from a wind farm and self-reporting no sleep disturbance and 18 controls living in a quiet rural area). Participants underwent full in-laboratory polysomnography during exposure to continuous WFN (25 dB(A)) throughout the night and a quiet control night (background noise 19 dB(A)) in random order. Group and noise condition effects were examined via linear mixed model analysis. Results Participants (30 females) were aged (mean±SD) 54.9±17.6 range: 18–80 years. Sleep efficiency in the control condition was (median [interquartile range]) objective: 85.5 [77.4 to 91.2]%; subjective: 85.7 [69.2 to 92.7]%) versus the WFN condition (objective: 86.1 [78.6 to 91.7]% subjective: 85.8 [66.2 to 93.8]%) with no significant main or interaction effects of group or noise condition (all p’s >0.05). Conclusion These results do not support that WFN at 25 dB(A) significantly impacts objective or subjective sleep efficiency in participants with or without prior WFN exposure or self-reported WFN-related sleep disturbance. Further analyses to investigate potential sleep micro-structural changes remain warranted.

P019 Obstructive sleep apnoea endotypes in people with multiple sclerosis

Purpose Obstructive sleep apnoea (OSA) is common in people with multiple sclerosis (MS) despite a lack of typical risk factors for OSA in people with MS such as obesity and male predominance. Therefore, underlying factors other than sex and obesity may be particularly important in the pathogenesis of OSA in people with MS. Thus, the primary aim of this study was to determine the relative contributions of OSA endotypes in people with MS and compare this to matched controls with OSA only. Methods Eleven people with MS and OSA (MS-OSA group) (apnoea-hypopnoea index [AHI]>5events/h) and eleven controls matched for OSA severity, age and sex without MS (OSA group) were studied. Participants underwent a detailed overnight polysomnography with an epiglottic pressure catheter and genioglossus intramuscular electrodes to allow for quantification of pathophysiological contributors to OSA. This included the respiratory arousal threshold, genioglossus muscle responsiveness, respiratory loop gain and upper airway collapsibility. Results Measures of the four primary OSA endotypes were not different between the MS-OSA and OSA groups (e.g. NREM respiratory arousal threshold -27±15 vs. -23±8 cmH2O respectively, p=0.24). Within group analysis indicated higher loop gain in non-obese MS-OSA participants compared to obese MS-OSA participants (0.53±0.11 vs. 0.37±0.11, p=0.04). Conclusions Overall, OSA endotypes are similar between MS-OSA participants and matched OSA controls. However, within the MS-OSA group, non-obese participants have higher loop gain (unstable respiratory control) compared to obese participants. Thus, unstable respiratory control may play an important role in OSA pathogenesis in many people with MS.

O043 “My Fitbit tells me I don’t sleep” – Validation of a consumer-wearable device (Fitbit Charge 3TM) using gold standard in-laboratory polysomnography to assess sleep in adults presenting for medical evaluation in a sleep laboratory

Background There has been a rapid growth in wearable devices marketed for sleep. Trackers such as the Fitbit collect data through an accelerometer and use heart rate variability to estimate the sleep-wake state. Currently, Fitbit validation studies have only been with “healthy” adults and Insomnia Disorder. Aims The purpose of this study is to evaluate the accuracy of Fitbit Charge3TM compared to in-lab polysomnography (PSG) in patients with sleep disorders. Our hypothesis is that Fitbit Charge 3TM will perform with less sensitivity and specificity relative to PSG in the presence of sleep disorders. Methods A prospective study of patients attending a PSG through Epworth Camberwell Sleep Lab between 2019–2021 will be conducted. Fitbit Charge3TM will be worn on the wrist with concurrent PSG monitoring. Parameters measured with both PSG and Fitbit Charge3TM will include total sleep time, Sleep onset latency, wake after sleep onset and time spent in N1, N2, N3 and REM sleep (min). Standard PSG data will be evaluated to diagnose sleep-disordered breathing. Progress to date:Ethics approval has been obtained, and 110 participants have been recruited. 30-second epoch-by-epoch analysis will now be conducted. Bland-Altman analyses will be performed to assess agreement between the Fitbit and PSG. Intended outcome and impact: Our novel study findings will provide evidence to address queries regarding the accuracy of the Fitbit trackers to evaluate sleep and may support the use of Fitbit Charge3TM as an initial screening device to assess sleep duration and sleep architecture in select patients.

P094 CPAP Service Patient Experience Survey

Introduction Increasing numbers of children with obstructive sleep apnoea require continuous positive airway pressure (CPAP) treatment. We aimed to collect feedback from parents/carers about our CPAP education and follow-up programme. Methods An online survey link was texted to families of children starting outpatient CPAP from Jan 2019 -Feb 2021. Questions assessed satisfaction with the CPAP initiation process, including education by our nurse educator (NE), mask fitting, using equipment, accessing help, confidence using CPAP and follow up. Open-ended feedback was invited. Results 17/55 (31%) of eligible families responded. “Very satisfied” responses regarding CPAP education ranged from 76% (discussion of costs) to 94% (machine use and maintenance). All families felt confident starting CPAP at home. Two reported issues starting CPAP, but reported feeling fully supported by staff remotely to troubleshoot. All families were “somewhat” or “very satisfied” with NE follow-up, with 2 families more neutral about physician follow-up. Two families reported lower satisfaction (“somewhat dissatisfied” or neutral) with the range of paediatric masks, rather than with the mask fitting process itself. Of 14 general comments, 64% were positive (most common theme was high standard of care from the NE); 21% negative (lack of mask choices, location of consulting suites); and 15% neutral. Suggestions for improvement included financial support information, support groups and online consumable ordering. Discussion Families feel confident and well supported to commence outpatient CPAP, highlighting the care, knowledge and support provided by our team. Findings emphasize the importance of a dedicated NE. Suggestions provided will inform future service improvements.

O037 Genioglossus motor control following the return to sleep after brief arousal

Rationale Arousal from sleep has been shown to elicit a prolonged increase in genioglossus muscle activity that persists following the return to sleep and may protect against airway collapse. We hypothesised that this increased genioglossal activity following return to sleep after an arousal is due to persistent firing of inspiratory single motor units (SMUs) recruited during the arousal. Methods 34 healthy participants were studied overnight while wearing a nasal mask/pneumotachograph to measure ventilation and with 4 intramuscular genioglossus SMU electrodes. During stable N2 and N3 sleep, auditory tones were played to induce brief (3-15s) AASM arousals. Ventilation and genioglossus SMUs were quantified for 5 breaths before the tone, during the arousal and for 10 breaths after the return to sleep. Results A total of 1089 tones were played and gave rise to 236 SMUs recorded across arousal and the return to sleep in 20 participants (age 23±4.2 years and BMI 22.5±2.2kg/m2). Ventilation was elevated above baseline during arousal and the first post-arousal breath (p<0.001). The peak firing frequency of expiratory and tonic SMUs was unchanged during arousal and return to sleep, whereas inspiratory modulated SMUs were increased during the arousal and for 4 breaths following the return to sleep (p<0.001). Conclusions The prolonged increase in genioglossus activity that occurs on return to sleep after arousal is a result of persistent activity of inspiratory SMUs. Strategies to elevate inspiratory genioglossus SMU activity may be beneficial in preventing/treating obstructive sleep apnea.