bluuebunny/crossref_metadata_2025 huggingface dataset:
P076 Safety of higher doses of melatonin in adults: A systematic review and meta-analysis
Authors: Menczel Schrire Z , Phillips C , Gordon C , Naismith S , Marshall N , Grunstein R
Published: November 2022

Introduction

Melatonin is commonly used for sleep and jetlag at low doses. There is less documentation on the safety of higher doses which are being increasingly used for a wide variety of conditions. This systematic review aimed to investigate the safety of higher doses of melatonin in adults.

Methods

We searched Medline, Scopus, Embase and PsycINFO databases from study inception until December 2019 with convenience searches until October 2020. The inclusion criteria were randomised controlled trials investigating high-dose melatonin (≥10mg) in human adults over 30 years of age. The outcomes examined were the number of adverse events (AEs), serious adverse events (SAEs) and withdrawals due to AEs. A meta-analysis was conducted on studies lasting 3 months or longer.

Results

79 studies were identified with a total of 3861 participants. 29 studies (37%) made no mention of the presence or absence of AEs. Only 4 studies met the pre-specified low-risk of bias criteria for meta-analysis. In that small subset, melatonin did not cause a detectable increase in SAEs (Rate Ratio=0.88 [0.52, 1.50], p=0.64) or withdrawals due to AEs (0.93 [0.24, 3.56], p=0.92), but did appear to increase the risk of AEs such as drowsiness, headache, and dizziness (1.40, [1.15, 1.69], p<0.001).

Discussion

There has been limited AE reporting from high-dose melatonin studies. Based on this limited evidence, melatonin appears to have a good safety profile. Better safety reporting in future long-term trials is needed to confirm this as our confidence limits were very wide due to the paucity of suitable data.
P079 A new lens on preschool sleep: Using wearable cameras to capture pre-bedtime activities
Authors: Miller L , Kuroko S , Meredith-Jones K , Taylor R , Taylor B , Russell-Camp T , Smith C , Galland B
Published: November 2022

Introduction

While bedtime routines are often recommended to address behavioural sleep problems in young children, these recommendations are based on parental subjective assessment of behaviours which may not be accurate. The aim of this study was to establish the feasibility of using wearable cameras to objectively measure bedtime routines and pre-bedtime screen use in preschool-aged children.

Methods

Sixteen children aged 3-4 years wore a GoPro video camera for two hours prior to bedtime on three consecutive evenings. Subsequent sleep parameters were monitored for seven nights by actigraphy. Standardised questionnaires and a sleep diary provided traditional measures of child sleep behaviours. Feasibility was determined by adherence to protocol and ability to develop a reliable behavioural coding scheme from the video data. Acceptability was determined through feedback questionnaires and exit interviews.

Results

Participant families found the cameras acceptable, with the majority of parents agreeing the cameras were easy to use (94%) and keep on their child (81%). Parents felt that wearing the camera did not change how they parented their child (88%), or their child’s behaviours (81%). A behavioural coding scheme incorporating self-care activities, nutrition, reading, physical contact and screen use (time, device type, media content) was successfully developed with interrater reliability established by two independent coders (kappa >0.8).

Conclusions

Wearable cameras provide a feasible and acceptable method to measure bedtime routines and screen use in preschool-aged children. This appears to be is the first study to use wearable cameras to objectively measure pre-bedtime activities in this age-group.
P080 State-dependency of nocturnal swallowing in healthy adults: Incidence, motor function and coordination with breathing
Authors: Monroe M , Carter S , Eckert D , Wallace E , Bilston L , Hudson A , Butler J , Gandevia S , Kerr G , Burke P
Published: November 2022

Introduction

Swallowing involves a complex motor pattern and coordination with breathing and other oro-motor behaviors. Sleep has major depressive effect on many of the motor neuronal pools that facilitate swallowing, particularly upper airway muscles. This study examines the state-depedence of the swallow motor program and coordination with breathing.

Methods

Adult subjects recruited from community undertook an overnight sleep laboratory study. Subjects were instrumented to monitor sleep (EEG), breathing (nasal mask, pneumotach), swallowing / airway valving events (epiglottic pressure, submental EMG) and pharyngeal muscle activity (peroral genioglosuss EMG electrodes).We report preliminary findings (N=5; 2 female; age: 23-57 yrs) from an ongoing study. Data reported mean ± SD.

Results

Nocturnal swallowing occurred intermittently thoughout the night, the majority triggered during an arousal from sleep (43-98% of all nocturnal swallows). Pharyngeal swallowing pressure was 147±44 cmH2O during quiet wake, 137±25 cmH2O during arousal from sleep, and 78 ± 23 cmH2O in stable sleep (p=0.02, RM-ANOVA). Swallows generated a brief, near-maximal burst of genioglossus EMG activity during quiet wake (90 ± 2 %, N=2) and during arousal from sleep (107 ± 24 %). In stable sleep, swallow EMG activity was 34 ± 1 %. Swallows during wakefulness occurred during expiration, the vast majority bracketed by expiration (Ex/Ex). Swallows in sleep, or during arousal from sleep, occurred in all phases of the respiratory cycle.

Conclusions

Swallows elicited during arousal from sleep generate ballistic EMG and pharyngeal pressures equivalent to wake state. In contrast, swallowing in stable sleep produces a markedly attenuated EMG and pharyngeal pressure.
P082 Lesson's learnt from an AOD team delivering a stepped-care intervention for sleep
Authors: Newman P , Oldenhof E , Swierzbiolek B , Andersonwurf J , Szeto J , Staiger P
Published: November 2022

Insomnia is a prevalent issue in AOD settings. Many use substances for their sedative effect or experience insomnia as a consequence of substance use, insomnia is a common feature of withdrawal and often linked to relapse.

In this study, a community-based AOD service is piloting a stepped-care intervention for insomnia. Nine AOD clinicians underwent CBT-I training to deliver a 3-step intervention: (1) a 60-minute information session, (2) A guided self-help booklet + ≤ 3 sessions with an AOD clinician, and (3) an 8-week CBT-I Group. The primary outcome is the insomnia severity index (ISI) and secondary outcomes relate to mental health and substance use. Focus groups and online questionnaires are being used to evaluate its implementation.

This presentation will outline how a stepped-care model for sleep treatment was integrated within an AOD setting and discuss the available evidence on its effectiveness, feasibility and acceptability. Of the 299 enrolled to date (M=57.4 years ±14.3yrs; 74.6% women), initial findings show significant improvements in ISI scores after Step 1 (17.5 to 15.6; P < 0.01) (d = 0.33), and 54% of eligible participants have moved into Step 2. So far, participant engagement and retention rates suggest good feasibility. Clinicians report high levels of satisfaction with the program, perceiving that it addresses an otherwise inconsistently met need, and enjoy the contrast in work to their usual role. Barriers to delivering the program include limited time and resources. Findings demonstrate this stepped-care program has the potential to improve outcomes and enhance recovery in AOD settings.
P083 Longitudinal changes in the sleep of patients of a multidisciplinary sleep clinic during the COVID-19 pandemic
Authors: Ng Y , Nguyen E , Bei B , Hamilton G , Rajaratnam S , Saunders W , Wellecke C , Mansfield D
Published: November 2022

Introduction

This study aimed to describe longitudinal changes of sleep in adult patients at a multidisciplinary sleep clinic throughout the COVID-19 pandemic.

Methods

Participants completed six self-report online surveys between October 2020 (during increased COVID-19 restrictions) and March 2022 (after easing of restrictions).

Results

Of 746 patients invited to participate in this study, 38 completed the initial and final surveys (mean age 53.9 years, range 21-83, 63.2% female). No participants had contracted COVID-19 at study commencement but 3 (7.9%) had been diagnosed with COVID-19 by the end of the study. In late 2020, 10 participants (26.3%) described reduced sleep quantity whilst 15 (39.5%) had worse sleep quality than pre-pandemic. Changes in dreams were reported by 13 participants (34.2%). In early 2022, 10 participants (26.3%) described worse sleep whereas 13 (34.2%) reported unaltered sleep and 3 (7.9%) experienced better sleep than pre-pandemic. Remaining patients were uncertain if their sleep had changed. No significant changes were detected in Insomnia Severity Index scores (initial survey mean 13.07, final survey mean 12.61, mean difference -0.47 [95%CI -2.29, 1.34], p=0.60) or PROMIS Sleep-Related Impairment 8a T-scores (initial survey mean 56.07, final survey mean 54.23, mean difference -1.84 [95%CI -4.12, 0.43], p=0.11).

Discussion

42% of patients experienced deterioration in sleep quantity and/or quality within the first year of the pandemic. Despite the easing of COVID-19 restrictions, there was no significant change in symptoms of insomnia and sleep-related impairment, and a quarter of patients reported that their sleep remained worse compared with before the pandemic.
P085 OSA-Onset: An algorithm for predicting the age of OSA onset
Authors: Olaithe M , Peppard P , Ravelo L , Barnet J , Hagen E , Eastwood P , Bucks R
Published: November 2022

Objectives

There is currently no way to estimate the period of time a person has had obstructive sleep apnoea (OSA). Such information is important in both clinical and research settings as it would allow identification of people who have experienced OSA for an extended period. People who are therefore, at greater risk of a range of other medical disorders; and enable consideration of the length of disease in the study of OSA pathogenesis or treatments.

Method

The ‘age of OSA Onset’ algorithm’ (OSA-Onset) was developed in participants of the Wisconsin Sleep Cohort (WSC) who had ≥2 sleep studies and were not using continuous positive airway pressure (n=696). The algorithm was tested in subsets of participants from the WSC (n=154) and the Sleep Heart Health Study (SHHS; n=705) who had an initial sleep study showing no OSA (apnea-hypopnea index (AHI) <15 events/hr) and a later sleep study showing presence of OSA (AHI≥15 events/hr).

Results

Regression analyses were performed to identify variables that significantly predicted change in AHI over time (BMI, sex, and AHI) and beta weights and intercept used in the subsequent algorithm. In the WSC and SHHS subsamples, OSA-onset was able to estimate disease onset with a mean absolute error of 7.8 and 5.5 years, respectively.

Conclusions

Future studies are needed to determine whether the years of exposure derived from the OSA-Onset algorithm is related to worse prognosis, poorer cognitive outcomes, and/or poorer response to therapy.
P090 Acceptability, Feasibility and Accuracy of Home Sleep Studies in Children with Neuromuscular Disorders
Authors: Pettigrew G , Lam J , Withers A , Wilson A
Published: November 2022

Introduction & Aims

Nocturnal hypoventilation may indicate declining pulmonary function in children with Neuromuscular Disorders (NMD). Hypoventilation is diagnosed with polysomnography (PSG), but there are significant barriers to the routine performance of PSG in this population. Home-based sleep studies (HSS) may reduce burden on patients and their families. We assessed the acceptability, feasibility and diagnostic accuracy of HSS for children with NMD.

Methods

11 participants, aged 5-15, underwent PSG. A HSS was conducted within two weeks for comparison that included measurement of transcutaneous carbon dioxide. Hypoventilation was defined as pCO2 >50mmHg for >25% of total sleep time. Acceptability was assessed by a survey completed by the families.

Results

Preliminary analysis shows HSS feasibility of 91% (10/11). Of 10 technically acceptable HSS, there was a concordant diagnosis in 9 (90%). Exploratory analysis shows higher total sleep time (529 vs. 431 minutes, p<0.05), slow wave sleep (132 vs. 99 minutes, p<0.05) and REM sleep (115 vs. 83 minutes, p<0.05) during HSS. Correlation was excellent between the percentage of total sleep time with pCO2 >50mmHg (κ=0.94, p<0.05) for PSG and HSS. 93% of families preferred HSS to laboratory PSG.

Conclusion

Preliminary analysis suggests home sleep studies that include transcutaneous carbon dioxide monitoring are feasible, acceptable and accurate when compared to PSG for diagnosing hypoventilation in children with NMD. These results imply that children may sleep better in the home environment. Further work is required to verify the diagnostic accuracy of home sleep studies in this group.
P091 Three generations of a family diagnosed with congenital central hypoventilation syndrome: A case series
Authors: Pimenta M , Saddi V , Thambipillay G , Teng A , Blecher G , Martin B
Published: November 2022

Introduction

Congenital central hypoventilation syndrome (CCHS) is an autosomal dominant disorder characterized by alveolar hypoventilation and autonomic dysregulation secondary to mutations of the PHOX2B genes.The disorder results in ventilatory impairment characterized by alveolar hypoventilation which worsens in sleep and occurs in individuals with otherwise normal pulmonary mechanics.Diagnosis is based on identification of a pathologic variant in the PHOX2B gene in absence of primary pulmonary, cardiac or neuromuscular disease or a causative brainstem lesion. We present five cases from three generations within the same family with varying degrees of phenotypic expression of the PHOX2B gene mutation.

Methods

The identification of CCHS in the index case after birth prompted evaluation of other family members.Genetic testing and counselling were performed for all family members. All family members with a confirmed diagnosis of CCHS underwent a complete assessment.

Discussion

We report the unique occurrence of CCHS among five members of a single family in three generations with a varying degree of penetrance and expressivity resulting in diverse clinical manifestations.Early diagnosis and adequate ventilatory management can prevent associated neurologic morbidity and improve long-term outcomes. Providing positive pressure ventilation (PPV) in infants and children with CCHS poses many challenges.Consistency is important as patients with CCHS require lifelong assisted ventilation, at least during sleep, and weaning of ventilation is not advisable.These five cases not only highlight the challenges of managing CCHS, but also the importance of genetic counselling and screening among first-degree relatives and extended family members.
Retracted: P093 Chronic Obstructive Pulmonary Disease – Obstructive Sleep Apnoea Overlap Syndrome – Prevalence in a Home ventilation service
Authors: Rajagopalan P
Published: November 2022

This article has been retracted. Please see: https://doi.org/10.1093/sleepadvances/zpad008
P097 Sleep, Fatigue and Depression in Young Autistic Adults
Authors: Richdale A , Morris E , Chetcuti L , Hayward S , Abdullahi I , Lawson L
Published: November 2022

INTRODUCTION

Poor sleep and fatigue are common in autistic adolescents and adults, who also experience increased depression compared with the general population. We examined the relationships between sleep quality, fatigue and depression in autistic young adults.

METHOD

Participants were 114 autistic young adults (15-25 years) from the Study of Australian School Leavers with Autism baseline survey (n=112; 57.1% male). From the survey we examined relationships between age, sex and the Autism Quotient-Short (AQ-S; autistic traits), Pittsburgh Sleep Quality Index (PSQI), Hospital Anxiety and Depression Scale (HADS-D) and the Flinders Fatigue Scale (FFS) using Spearman’s Correlation. We then investigated whether FFS mediated the relationship between the PSQI and HADS-D (PROCESS macro; 1000 bootstrapped resamples). Due to missing data, not all individuals are included in reported analyses.

RESULTS

38% (n=83) of participants had depression, 57% (n=94) poor sleep, and 36% (n=73) fatigue. HADS-D was positively associated with PSQI (p<.001) and FFS (p<.001). Increased PSQI and FFS were associated with sex (female) and increased AQ-S (all p<.01). The full mediation model accounted for 25% of variance in depression (p<.001) with a significant indirect effect of sleep quality on depression through fatigue. The direct effect of sleep quality on depression was not significant after fatigue was included in the model.

CONCLUSIONS

Findings indicate poor sleep and fatigue play a role in the maintenance of depression in autism. Further replication in larger and longitudinal cohorts is needed. Like non-autistic individuals with depression, sleep and fatigue may be important treatment targets for treating depression in autism.
P098 "It's just [complicated] sleep": Discourses of sleep and ageing in the media
Authors: Ross I , Breheny M , Ladyman C , Signal L , Dew K , Gibson R
Published: November 2022

Background

Sleep disturbances have been reported to increase with older age. However, sleep-related beliefs and practices also appear to change with ageing and disease, having implications for measurement and management of sleep among older people. Analysis of sleep-related messaging within mainstream media contributes to understanding social discourses of sleep and ageing.

Method

Texts from New Zealand’s main free online news source “Stuff” were collated using key words “sleep” together with ''ageing'', ''older'', ''elderly'', or ''dementia'' between December 2018 and December 2021. A total of 38 relevant articles were collated. A critical discourse analysis was used to describe the texts then interpret them in relation to discursive practices and wider social explanations.

Findings

Texts were categorised under basic contextual themes: general ageing, disease, beauty, and treatments. Discursive constructions described an inevitable decline of sleep with ageing, including the tensions between a likely physiological decline alongside individual failures to achieve good sleep; sleep’s role as both a remedy and risk for diseases (such as dementia); and the simplification of solutions for self-managing sleep alongside recognition of the complexity of sleep.

Conclusions

Social discourses of sleep and ageing within the mainstream New Zealand media were subtle and contradictory. Punctured with tensions between endorsing sleep practices and purchases to prevent age-related decline whilst also asserting that decline is inevitable due to the complexity of the ageing body and modern society. Findings will inform future research in the field of sleep as a concept and practice among older people.
P102 Sleep health management practices in Australian residential aged care facilities: The perspective of registered nurses
Authors: Chen E , Fernandez T , Basheti M , Gordon C , Saini B
Published: November 2022

Background

Sleep disturbances are commonly experienced by older people living in residential aged care facilities. Non-pharmacological approaches have a strong evidence base, however research shows that medications (sedatives, antidepressants, antipsychotics) are often used inappropriately. However, little is known about healthcare professionals’ current sleep health management approaches in residential aged care facilities.

Aims and objectives

This study aimed to explore the current sleep health management practices in Australian residential aged care facilities and investigate potential ways to improve non-pharmacological and pharmacological sleep health practices in the future.

Design

Qualitative inductive thematic analysis of semi-structured interviews guided by COREQ guidelines.

Methods

Semi-structured interviews were to be conducted with registered nurses and aged care pharmacists recruited using a convenience-sampling and snowballing approach. Interviews were audio-recorded, transcribed verbatim and inductively analysed for emergent themes.

Results

Fourteen interviews were conducted with registered nurses in New South Wales. Thematic analysis derived three main themes: 1) Awareness and observations of sleep health, 2) Healthcare approach to sleep health management in residential aged care facilities and, 3) Organisational constraints to evidence-based sleep health care provision.

Conclusion

Registered nurses assess residents’ sleep health and attempt to manage sleep health through both non-pharmacological and pharmacological strategies. Organisational culture and staffing ratios negatively impact the delivery of best evidence-based practice but effective communication between the multidisciplinary team appears to facilitate management of sleep disturbances. Participants emphasized the need for sleep health educational programs and the development of national sleep health management guidelines across aged care in Australia.
P103 Associations between sleep regularity, OSA and hypertension in a middle-aged community population
Authors: Sansom K , Reynolds A , Windred D , Phillips A , Walsh J , Maddison K , Singh B , Eastwood P , McArdle N
Published: November 2022

Little is known about the association of irregular sleep patterns with obstructive sleep apnoea (OSA) and hypertension. This study examined whether irregular sleep patterns determined by the sleep regularity index (SRI) were associated with OSA and hypertension, and whether SRI modified the known association between OSA and hypertension. 635 adults (age mean[range]=57[42-77]years, female=58.6%) from the community-based Raine Study who were not current shift workers were assessed for OSA (in-laboratory polysomnography, AHI ≥5events/hour; time spent with oxygen saturation <90% (T90) ≥median), hypertension (doctor diagnosed or systolic BP ≥140mmHg and/or diastolic ≥90mmHg) and sleep (maximum 7 days of wrist actigraphy). The SRI was calculated from actigraphy (≥4 days) based on variation in usual sleep and wake times. Participants were categorised as regular sleepers (first tertile), average sleepers (second tertile), or irregular sleepers (third tertile). Logistical regression models examined the independent and combined associations between SRI, OSA and hypertension. Covariates included age, sex, body mass index, actigraphy sleep duration, insomnia, depression, activity, alcohol, smoking and anti-hypertensive medication. Compared to regular sleepers, irregular sleepers had increased odds of OSA defined by the AHI (OR 1.77 95% CI 1.10-2.83) and T90 (OR 1.69 95% CI 1.10-2.61) but not hypertension. There was no difference in hypertension odds for regular and irregular sleepers when the data were stratified by participants with and without OSA.

Individuals with OSA are more likely to have irregular sleep patterns, which might exacerbate associated adverse health outcomes. However, irregular sleep patterns do not appear to modify the association between OSA and hypertension.
P108 Association of drowsiness events with a combination of sleep loss and other work metrics
Authors: Shekari Soleimanloo S , Sletten T , Clark A , Cori J , Wolkow A , Beatty C , Shiferaw B , Barnes M , Tucker A , Anderson C , Rajaratnam S , Howard M
Published: November 2022

Introduction

Heavy vehicle drivers (HVDs), carrying approximately 75% of non-bulk domestic freight on Australian roads, are at risk of drowsiness due to night-time, long drives, or short sleep. Drowsiness comprises 46% of all driver-impairment-related factors in HVDs fatalities. However, the specific role of sleep loss in HVDs' drowsiness is less known. This study assessed the association of sleep loss, independent of other work metrics, with real-time drowsiness in HVDs.

Methods

Eight HVDs aged 49.8± 8 years, 27± 10.3 years of experience, worked for 3-28 (13± 6) shifts. A composite ocular measure of drowsiness (John's Drowsiness Score) and drivers' sleep-wake was monitored by Optalert glasses and Actiwatches, respectively. The drowsiness event (response variable) was defined as at least one event of JDS≥ 2.6 /h, and sleep loss (exposure) as the variation of sleep opportunity pre-shift from the 9-hour recommended rest break in Europe. Multivariate logistic regression assessed the odds of drowsiness events under sleep loss when adjusted for time of day, shift start time and hours of drive.

Results

Data comprised 1061 observations of work metrics or JDS and 694 records of sleep duration. Sleep loss ranged from 1 to 6.3 hours (3.4 ± 1.1h). Compared with a 1- 2.5-hour sleep loss, sleep loss> 4 hours doubled the likelihood of drowsiness events when controlled for other covariates (p=0.019).

Discussion

Sleep loss increases the odds of drowsiness events in HVDs with similar work schedule metrics. Further research should assess if Australia's 7-h minimum break provides adequate sleep under different schedule conditions.
P109 Predicting major adverse cardiovascular events using symptom subtypes of severe obstructive sleep apnoea
Authors: Shenoy B , McArdle N , Walsh J , Cadby G , Hillman D , McQuillan B , Hung J , Dhaliwal S , Mukherjee S , Palmer L , Singh B
Published: November 2022

Background

Obstructive sleep apnoea (OSA) is a complex heterogeneous disorder, and patients with similar disease severity present with different symptom profiles and outcomes. It is unclear whether OSA symptom subtypes independently predict incident major adverse cardiovascular events (MACE).

Method

Consecutive patients attending a tertiary sleep clinic from 2006 to 2010 were prospectively investigated and linked to administrative health data. Data from 1,767 patients with severe OSA (apnoea-hypopnoea index ≥30 events/hour) were used in latent class analysis to identify symptom subtypes. Associations between symptom subtypes and incident MACE were assessed using Cox proportional hazards models, with adjustment for known cardiovascular risk factors.

Results

On average, patients were middle-aged (mean±

SD

52.5±13.2 years), obese (BMI, 35.4±7.9 kg/m²), and male (71.7%). Four symptom subtypes were identified: high symptom burden: severe sleepiness (26.0%), high symptom burden: sleep onset insomnia (34.8%), moderate symptom burden (18.4%), and minimal symptoms (20.7%).

Over a median follow-up of 7 years, 330 (18.7%) patients developed MACE. After adjustment for covariates, the high symptom burden: sleep onset insomnia subtype was associated with increased risk for MACE relative to those with moderate (HR, 1.59; 95%CI, 1.12–2.25; P=0.010) or minimal (HR, 1.47; 95%CI, 1.07–2.03; P=0.018) symptom burden.

Discussion

Distinct symptom subtypes can be identified among severe OSA patients. In symptomatic patients, those with a high prevalence of sleep onset insomnia were at increased risk of MACE, relative to those with moderate or minimal symptom burden. Our findings suggest that symptom subtypes may be clinically relevant in risk stratification for MACE in severe OSA.
P114 How should we classify on-call workers? A proposed taxonomy for modern working arrangements
Authors: Sprajcer M , Appleton S , Adams R , Gill T , Ferguson S , Vincent G , Paterson J , Reynolds A
Published: November 2022

Introduction

Research and guidance materials addressing on-call work typically focus on a narrow set of industries (e.g., emergency services, healthcare). However, modern working arrangements are changing. The casualisation of many industries, combined with the rise in online and app-based working arrangements, means that many workers who can be called to work are not included in current on-call literature. We therefore present a proposed taxonomy for classifying a broader range of on-call workers, based on the work and sociodemographic characteristics of on-call workers in Australia.

Methods

Work arrangements and sociodemographic factors of 1057 Australian adults were assessed in a survey. Questions addressed on-call work undertaken in the previous three months, occupation, work hours, and any non-standard working conditions.

Results

At least one workday characterised as ‘on-call’ was reported by 45.5% of respondents, with a higher prevalence in younger individuals (63.1% of respondents aged 18–24 years reported working on-call). On-call work was reported in a range of industries, including management, community and personal service workers, sales workers, machinery operators, and drivers.

Discussion

Findings suggest that previous reports of on-call work prevalence (typically based on traditional on-call industries such as emergency services) likely underestimate the proportion of individuals who consider themselves on-call workers. As a result, on-call work requires a novel classification system that is able to capture non-traditional on-call work and can differentiate between types of on-call working arrangements. A taxonomy including traditional on-call work, gig economy work, relief, or unscheduled work, and out of hours work is presented.
P116 Increased airflow limitation during nocturnal respiratory events is associated with increased psychomotor vigilance task lapses in obstructive sleep apnoea patients
Authors: Staykov E , Mann D , Duce B , Kainulainen S , Leppänen T , Töyräs J , Sands S , Terrill P
Published: November 2022

Introduction

Impaired daytime vigilance is common in obstructive sleep apnoea (OSA) patients. However, the apnoea-hypopnea index (AHI) has been shown to have a weak correlation with daytime vigilance. This may be because the AHI only quantifies respiratory event frequency. Thus, we aimed to test our hypothesis that increased airflow limitation during nocturnal respiratory events is associated with daytime vigilance impairment.

Methods

495 OSA patients (AHI≥5) completed a psychomotor vigilance task (PVT) and in-lab polysomnographic recording. The number of lapses (response time >500ms) was the primary outcome. Airflow limitation was quantified from nasal airflow using a validated algorithm. Linear regression models were adjusted for age, sex, and body mass index.

Results

The percentage of flow-limited breaths during respiratory events was associated with the number of PVT lapses (R=0.119, p<0.05); AHI was not (p>0.05). One standard deviation (SD, 20%) increase in the percentage of flow-limited breaths during respiratory events increased the number of lapses by 2.5. This effect-size was greater than that for age (one SD increase, 12.5 years, increased the number of lapses by 1.3). These results were similar after adjusting for AHI, arousal index, and desaturation event area. Similar findings were observed using the percentage of flow-limited breaths during all sleep.

Discussion

Increased airflow limitation during nocturnal respiratory events was associated with decreased daytime vigilance in OSA patients. This association appeared to be independent of respiratory event frequency, arousal frequency, and hypoxaemia severity. This suggests that disproportionately large ventilatory drive versus achieved ventilation (i.e. flow-limitation) contributes to daytime vigilance impairment.
P121 Turnaround times for the submission of information using a novel suite of fully online patient forms
Authors: Teuwen P , Eriksson N , Scott A
Published: November 2022

Purpose

To assess the turnaround times for a newly implement suite of online patient questionnaires and forms returned to a private Thoracic and Sleep outpatient service over a two-week period.

Methods

This study included all online patient forms submitted to the Wesley Hospital Sleep Disorders Centre and Wesley Hospital Lung Function Lab between the 16th and 30th June (n= 120). Age, gender and turnaround times were included in the data set.

Results

The average turnaround time for form submission was 2.7 days. 95% of forms were returned within 7 days, 43.3% were returned the same day. On Average women submitted their forms (2.5 days) faster than men (2.8 days). Patients aged under 40 had the shortest average turnaround time (2.53 days). However, when gender is considered we found that women aged over 60 had the fastest turnaround time (2.0 days) and women aged between 40 and 60 had the slowest average turnaround time (3.5 days).

Discussion

It is clear that online form completion and submission are no barrier to the rapid provision of information to and from patients. While failed submission attempts were not included in this analysis, anecdotally we found that most patients had little to no difficulty with completing an online form. The sample size of this study may have limited some of the findings, particularly when assessing the sub-groups that included both age and gender combined.
P124 Differences in OSA pathophysiological traits between mandibular advancement therapy responders versus non-responses and the influence of obesity
Authors: Tong B , Chiang A , Naik G , Osman A , Bull C , Donegan M , Pinczel A , Rawson G , Pitcher G , Brown E , Kwan B , Mukherjee S , Adams R , Eckert D
Published: November 2022

Mandibular advancement therapy (MAS) is a recognised second-line therapy for obstructive sleep apnoea (OSA). However, MAS treatment outcomes vary and are difficult to predict. Recent studies have investigated the role of OSA endotypes to predict MAS therapy outcomes. However, whether OSA endotype predictors differ between obese and non-obese people with OSA is unknown. Thus, this study aimed to compare OSA endotypes between responders and non-responders to MAS therapy in obese and non-obese individuals.

90 people with OSA (AHI>10events/h) were studied. OSA was confirmed via in-laboratory polysomnography. A detailed physiology night was subsequently performed prior to MAS therapy. OSA endotypes were estimated from the detailed physiology polysomnography using a custom-designed, validated, semiautomated script. OSA endotypes were compared between responders (residual AHI<10events/h) and non-responders to MAS therapy. Further comparisons were made between obese and non-obese groups.

Responders to MAS therapy had a less collapsible upper airway; Vpassive: 93[88,96]vs.85[62,94]%Veupnea,p=0.003); Vactive: 103[95,112]vs.98[16,104] %Veupnea,p=0.008), better pharyngeal muscle compensation Vcomp: 9.8[4.3,19.6]vs.3.3[-19.1,18.6]%Veupnea,p=0.02), lower arousal threshold (114[109,144]vs. 142 [117, 177]%Veupnea,p=0.006) and tended to also have lower loop gain (0.48 ±0.1vs. 0.42±0.1,p=0.05). . These findings were similar in obese versus non-obese individuals although loop gain was significantly lower in responders versus non-responders in the non-obese (p=0.01) but not the obese group (0.97).

MAS therapy was most beneficial in people with a less collapsible upper airway, good pharyngeal muscle compensation, lower arousal threshold and loop gain at baseline. Prospective assessment of OSA endotypic traits may therefore help guide treatment decisions and improve MAS therapy outcomes.
P126 The impact of inadequate sleep and breaking up sitting during the day on simulated driving performance
Authors: Tuckwell G , Vincent G , Gupta C , Ferguson S
Published: November 2022

Introduction

Inadequate sleep and prolonged sitting are both associated with a reduction in psychomotor functioning, a cognitive process crucial for the safety critical task of driving. Regular bouts of light-intensity physical activity have been shown to improve psychomotor function. However, it is unknown if breaking up sitting during the day can improve psychomotor functioning for the task of driving, particularly during the commute home when drivers may be at a higher risk of fatigue.

Method

Healthy participants (n=81, 49%female, age 23.6 ± 4.5 years ) participated in a 7-day laboratory study (1 adaptation, 5 experimental, 1 recovery). Participants were randomly allocated to a condition: sitting and 9-h sleep (Sit9; n=22), breaking up sitting 9-h sleep (Sit9; n=19), sitting and 5-h sleep (Sit5; n=21) and breaking up sitting 5-h sleep (Break5; n=19). Participants allocated the breaking up sitting conditions completed 3-min of light-intensity walking every 30 minutes between 09:00-17:00h, while participants in the sitting group remained seated. Driving performance was measured via speed and lane variability during a 20-min simulated drive at 08:10 and 17:30 for the 5 experimental days.

Results

Mixed model analyses revealed no significant interaction effects between condition and time of commute between Sit9, Break9, Sit5 and Break5 for driving performance.

Discussion

Breaking up sitting did not improve driving performance during the commute home. These findings highlight that light-intensity walking may not be adequate to overcome the effects of inadequate sleep on diving performance. Future studies should explore if higher intensity physical activity produce changes in driving performance.
P127 Study protocol for examining the role of REM sleep in trauma-recovery mechanisms: REM fragmentation and fear inhibition in adults with insomnia disorder before and after cognitive behavioural therapy for insomnia (CBT-I)
Authors: Vuong V , Mellor A , Risbrough V , Bei B , Drummond S
Published: November 2022

Introduction

Insomnia has been shown to increase by 2.5-3 fold the risk of developing posttraumatic stress disorder (PTSD) after a traumatic event. The mechanism underlying this increased risk, however, remains unknown. We postulate insomnia may be contributing to PTSD by disrupting rapid eye movement (REM) sleep in the same way it has been shown to impair fear inhibitory processes, which are central to the natural recovery from trauma. To test this, the following protocol aims to: (1) examine the relationship between REM sleep fragmentation and fear inhibition in insomnia; and (2) examine whether correcting REM fragmentation by treating the insomnia, in turn, improves fear inhibition.

Methods

Ninety-two adults with insomnia disorder will be randomly allocated to an active treatment or waitlist control condition. Active treatment involves 7 weekly sessions of cognitive behavioural therapy for insomnia (CBT-I) with a clinician via telehealth. REM fragmentation and fear inhibition (i.e., safety learning and extinction recall) will be assessed pre- and post-treatment in a 4night/3day testing protocol via at-home polysomnography and the fear-potentiated startle paradigm, respectively.

Discussion

This study aims to be the first to test an underlying mechanism potentially explaining why insomnia greatly increases PTSD risk, while demonstrating an existing clinical intervention (CBT-I) can be used to improve this mechanism. Findings will have potential clinical implications for novel approaches in the prevention, early intervention, and treatment of PTSD.
P128 Effect of acute exercise on stress and working memory following sleep restriction
Authors: Wallace-Webb J , Michiel C , Service T , Watkinson O , Harding D , Mulligan G , Stuart-Hill L
Published: November 2022

Introduction

Cognitive impairment poses a serious risk to worker safety. We investigated the interacting effects of acute exercise and sleep restriction (SR) on stress and working memory (WM).

Methods

Our randomized crossover design had 14 adults (10 M, 23 ± 3 years) complete two sessions under different sleep conditions (normal sleep (NS)=8h; restricted sleep (RS)=4h). Sleep duration was verified by validated wrist-worn actigraphy (Fitbit tracker). Salivary cortisol levels (stress indicator) and WM (via n-back task performance) were measured before and after high-intensity exercise on a cycle ergometer. Data was collected at the same time of day for each participant and a washout interval of at least 72-hours separated experimental conditions.

Results

A two-factor repeated measure ANOVA revealed sleep condition to have a significant effect on cortisol levels (F(1,13)=7.78, p<0.05) and n-back reaction time (RT) (F(1,13) = 10.54, p<0.01), but not response accuracy. Post-hoc dependent t-tests showed that RS lead to slower RTs compared to the NS condition (t(27)=3.32, p<0.01), as well as higher cortisol levels both before (t(13)=2.22, p<0.05) and after (t(13)=2.64, p<0.05) exercise. Acute exercise did not affect cortisol levels, but did appear to have a facilitative effect on response accuracy (t(27)=2.13, p<0.05), as well as RT in both sleep conditions (

ES

t(13)=2.32, p<0.05.

RS

t(13)=2.2, p<0.05).

Discussion

These findings suggest that RS may lead to increased stress and impaired cognitive function, while acute exercise may serve as an effective tool for counteracting the negative cognitive effects induced by SR.
P131 Factors associated with Referral to Sleep Clinic and Diagnosis of Obstructive Sleep Apnoea in Pregnant People with Class III Obesity
Authors: Warhurst S , Sethna F , Georgousopoulou E , Huang C
Published: November 2022

Background

Obstructive Sleep Apnoea (OSA) in pregnancy is associated with increased maternal and neonatal morbidity. Evidence supporting use of traditional screening tools (e.g. Epworth Sleepiness Scale and STOP-BANG) in pregnancy is inconsistent, especially for people with class III obesity. This study aims to determine factors associated with referral to sleep clinic and diagnosis of OSA in pregnant people with class III obesity.

Method

Retrospective audit of records for people with class III obesity seen in high-risk pregnancy clinic at Canberra Hospital between 1/7/20 and 30/6/21. It will a) describe patient factors associated with referral to sleep clinic and b) describe patient factors associated with diagnosis of OSA (apnoea-hypopnoea index ≥5).

Progress to date

Approval to proceed as quality improvement project by ACT Health Ethics Committee. Data collection will be completed in 4-8 weeks. Preliminary results will be available by September-October 2022.

Intended outcome and impact

Clinical parameters associated with sleep clinic referral will be presented and compared to existing evidence. Initial data screening suggests that referral rates to sleep clinic are low and reasons for this will be explored. Clinical features associated with a diagnosis of OSA in those who proceeded for polysomnography will also be presented. Our results will inform local practice to determine if pregnant people with class III obesity are being appropriately referred to sleep clinic and objectively assessed for OSA. Our research will add to the limited research in this area and inform further prospective studies on effective screening in this population.
P134 Sleep Laboratory contact in adults commencing CPAP: a post-hoc analysis of the AHEAD trial
Authors: Webster K , Ellender C
Published: November 2022

Background

CPAP used for >4hrs/night effectively treats obstructive sleep apnoea(OSA), however CPAP adherence is often poor. A randomised control trial from our department demonstrated improved CPAP adherence at 12 months in patients receiving video education (VE), compared with standard of care education (SOCE) at CPAP commencement. This follow-on study aimed to evaluate 12-month clinic utilisation of patients in the AHEAD trial, hypothesizing that increased unscheduled contact by patients in the intervention arm may contribute to improved CPAP adherence.

Methods

Post-hoc analysis of data from the AHEAD trial was performed. The AHEAD trial included 195 patients recruited from a large trial protocol and randomised to either SOCE or SOCE+VE. Demographics including age, gender, education level and socioeconomic indices were collected. CPAP usage was assessed at 2-, 6-, and 12-months post randomisation. Adequate adherence was defined as usage >4hours/night. Further data on number of scheduled and unscheduled visits at 12-months post randomisation was collected. The primary outcome was number of unscheduled visits in intervention vs control arm.

Progress to date

Study groups were well-matched at baseline. The proportion with adequate CPAP usage at 12mths was higher in the VE group (33, 33% versus 48, 50% p=0.01). Preliminary analysis suggests there are no significant differences in number of unscheduled visits at 12-month follow up between SOCE vs SOCE+VE (mean0.29 vs 0.43 p=0.18). Further analysis will investigate predetermined subgroups – including low educational level / socioeconomic status.

Intended outcome and impact

This study will inform strategies to improve CPAP adherence in patients with OSA.
P135 Intervention adherence and usefulness as predictors of the efficacy of Cognitive Behavioural Therapy for Insomnia during perinatal periods
Authors: Wellecke C , Cassera L , Quin N , Pinnington D , Spina M , Bei B
Published: November 2022

Introduction

One third of birthing parents experience insomnia symptoms during perinatal periods. Cognitive Behavioural Therapy for Insomnia (CBT-I) is effective for perinatal insomnia. However, it is unclear how adherence to and perceived usefulness of individual CBT-I components predict treatment efficacy.

Methods

76 nulliparous birthing parents (age M±SD=33.07±3.10) with prenatal insomnia received CBT-I from two randomised controlled trials. Insomnia symptoms, sleep-related impairment, dysfunctional beliefs and attitudes about sleep (DBAS), and adherence and usefulness were self-reported at 30 and 35-weeks gestation, and 2 and 6-months postpartum. Linear regressions assessed whether adherence and usefulness predicted sleep-related outcomes, controlling for age, mental health history and social support.

Results

Adherence and perceived usefulness decreased over time across all components. “Cognitive restructuring” and “sleep hygiene” had the highest usefulness and adherence ratings, while “relaxation and mindfulness” was the least useful and adhered to. Controlling for covariates, higher adherence to “sleep hygiene” predicted lower DBAS at 35-weeks gestation (p=.024). At 6-months postpartum, higher usefulness of “relaxation and mindfulness” predicted lower DBAS (p=.032), and higher usefulness/adherence to “managing sleep deprivation, sleepiness, and fatigue” predicted lower insomnia symptoms (usefulness p=.003; adherence p=.029) and lower sleep-related impairment (usefulness p=.007). No significant relationships were found between sleep-related outcomes and usefulness/adherence to other CBT-I components (i.e., psychoeducation, cognitive restructuring, and stimulus control).

Conclusion

Individual CBT-I components play different roles in treatment efficacy as birthing parents navigate diverse sleep challenges in perinatal periods. Strategies to enhance adherence to and perceived usefulness of relevant treatment components for specific perinatal milestones may enhance efficacy.
P136 Sleep Quality and Obesity: an investigation into the relationship between obesity and poor sleep quality as measured by polysomnography
Authors: Wells S , Inman D , Huang H
Published: November 2022

Background

Studies have demonstrated a link between obesity and poor sleep quality. However, definitions of sleep quality vary, and are often subjective. Furthermore, these studies do not explore whether this link is independent of comorbidities associated with obesity. We aim to establish whether an independent link exists between poor sleep and obesity, with sleep quality measured objectively through polysomnography.

Methods

A retrospective observational study of patients undergoing level 1 or 2 diagnostic polysomnography over one year. We recorded demographics, body mass index (BMI), comorbidities; and polysomnography data including apnoea-hypopnoea index, total sleep time (TST), percentage slow-wave sleep (%SWS) and percentage rapid eye movement (%REM) sleep. Primary outcome was %SWS, with secondary outcomes TST, %REM sleep and O2 nadir. Linear regression analysis was used to investigate correlations between variables and the outcomes proposed.

Progress to Date

297 patients were included. The average BMI was 37.9 (17.8-79.5). BMI was not significantly correlated with %SWS. Howevere, a significant negative correlation was found between BMI and %REM (β = -0.196, p = 0.013), BMI and TST (β = -0.199, p = 0.018) as well as BMI and O2 nadir (β = -0.140, p = 0.054). Statistical analysis is ongoing, and additional interesting correlations are being explored.

Intended Outcome and Impact

To investigate if an independent correlation between obesity and abnormal sleep architecture exists. To explore if commonly associated obesity comorbidities are significantly correlated with polysomnographic indices of sleep quality, to help target interventions aimed at both investigating and improving sleep quality.