bluuebunny/crossref_metadata_2025 huggingface dataset:
O020 What helped you and what prevented you from getting good sleep? Contribution of daily facilitators and barriers to adolescent sleep
Authors: Maskevich S , Shen L , Wiley J , Drummond S , Bei B
Published: October 2021

Introduction

This intense longitudinal study examined factors that facilitate and hinder sufficient and good quality sleep in adolescents’ everyday life.

Methods

205 (54.2% female, 64.4% non-white) Year 10–12 adolescents (Mage = 16.9 ± 0.9) completed daily morning surveys and wore actigraphy over 2 school-weeks and 2 subsequent vacation-weeks. Morning surveys assessed self-reported sleep and the usage of 8 facilitators and 6 barriers of sleep from the previous night. Linear mixed-effects models examined contribution of facilitators/barriers to actigraphy and self-reported total sleep time (TST) and sleep onset latency (SOL), controlled for age, sex, race, place of birth, and study day. Schooldays/non-schooldays was included as a moderator.

Results

Seven facilitators and two barriers were endorsed by high proportions (>30%) of adolescents as frequently (≥50% days) helping/preventing them from achieving good sleep.

Facilitators predicting longer TST and shorter SOL, were: “follow body cues”, “manage thoughts and emotions”, “create good sleep environment”, “avoid activities interfering with sleep” and “plan bedtime and go to bed as planned” (only TST on schooldays). Barriers predicting shorter TST and longer SOL, were: “pre-bedtime thoughts and emotions”, “unconducive sleep environment”, “activities interfering with sleep”, “inconsistent routines” and “other household members’ activities”. Overall, facilitators or barriers explained an additional 1–5% (p-values < .001) of variance beyond the covariates.

Discussion

Adolescents perceive a range of factors as facilitating and as preventing sufficient and good quality sleep in everyday life. These factors are predictive of their sleep duration and onset latency, and need further research to understand their functions and clinical implications.
O024 Weight loss surgery in obese patients with obstructive sleep apnoea is associated with increased inter-hemispheric electroencephalographic coherence
Authors: Duce B , Ryan A , Hukins C
Published: October 2021

Introduction

Electroencephalogram (EEG) analysis of obstructive sleep apnoea (OSA) patients has shown reductions in both delta band frequency power and interhemispheric coherence. Weight loss surgery is increasing in popularity and is often effective in reducing the symptoms and severity of OSA. No study has examined the effects of weight loss surgery on the sleep EEG of OSA patients.

Methods

Twenty patients underwent diagnostic polysomnography (PSG) prior to- and twelve months after weight loss surgery. Quantitative EEG analysis was conducted to calculate spectral power (fast fourier transform with four second overlapping windows) as well as amplitude and phase coherence between the two hemispheres (C3/C4 electrodes).

Results

Weight loss surgery was successful in reducing weight (137±17 kg vs 102±17kg P<0.001 for pre- and post-surgery, respectively), and OSA severity (Apnoea-Hypopnoea Index: 26±15 events/hour vs 10±12 events/hour P<0.001 for pre- and post-surgery, respectively). Stage N1 proportions were slightly decreased (12±7% vs 9±8%; P=0.039 for pre- and post-surgery, respectively) but all other stages were unchanged. Increases in interhemispheric phase coherence was observed following weight loss surgery, with significant changes observed in theta (-0.07±0.09 degrees vs -0.03±0.03 degrees P=0.035), alpha (-0.12±0.13 degrees vs -0.03±0.06 degrees P=0.008), sigma (-0.19±0.18 degrees vs -0.07±0.07 degrees P=0.011) and beta (-0.29±0.25 degrees vs -0.11±0.09 degrees P=0.004) band frequencies. There were no differences in EEG spectral power or interhemispheric amplitude coherence.

Discussion

Sleep EEG coherence, a putative marker of neurocognitive susceptibility in OSA, improves following weight loss surgery. Further studies are needed to determine the functional consequences of these EEG changes.
O029 Predictors of acute insomnia during the COVID-19 pandemic beyond perceived stress
Authors: Meaklim H , Varma P , Finck W , Junge M , Jackson M
Published: October 2021

Introduction

Stress is a common precipitant of acute insomnia and likely contributed to increased reports of sleep disturbances during the COVID-19 pandemic. However, many other sleep and lifestyle changes may have also precipitated acute insomnia. This study aimed to clarify which factors, beyond perceived stress, contributed to the development of acute insomnia during the COVID-19 pandemic.

Methods

The study consisted of 578 participants with acute insomnia and 741 good sleepers. Participants completed an online survey assessing insomnia symptoms, sleep, lifestyle changes and mental health during the COVID-19 pandemic. Logistic regression analyses were conducted to identify contributing factors to acute insomnia when controlling for demographic differences between groups.

Results

Perceived stress was a significant predictor of acute insomnia during the pandemic (p<.001). However, after adjusting for stress, individuals who altered their sleep timing (p<.001) or increased their use of technology before bed (p=.037) during the pandemic were at a 3-fold increased risk of acute insomnia. Other sleep factors associated with acute insomnia included dream changes (p=.001), sleep effort (p<.001), and cognitive pre-sleep arousal (p<.001). For pandemic factors, being very worried about contracting COVID-19 (p<.002) and more stringent COVID-19 government restrictions (p<.001) increased the risk. Anxiety (p<.001) and depressive (p<.001) symptoms, as well as the personality trait of agreeableness (p=.010), also contributed to acute insomnia.

Discussion

To reduce acute insomnia during the COVID-19 pandemic, public health messaging should promote stress reduction and mental health care, but also modifiable behaviours such as keeping consistent sleep patterns and reducing technology use before bed.
O036 Respiratory event related oxygen desaturation is predictive of cardiovascular mortality in sleep apnoea patients
Authors: de Chazal P , Dissanayake H , Cook K , Bin Y , Sutherland K , Cistulli P
Published: October 2021

Introduction

Cardiovascular disease (CVD) is the leading cause of death globally. The mechanisms underpinning the development of CVD in OSA are multifaceted and include sympathetic overactivity, endothelial dysfunction, inflammation, and oxidative stress. Nocturnal hypoxaemic burden—the cumulative exposure to hypoxaemia experienced overnight—may contribute to the pathophysiology of CVD. We investigated if polysomnogram SpO2 parameters can predict CVD outcomes in OSA patients.

Methods

Data from the SpO2 signals from 4689 polysomnograms (PSGs) of the Sleep Heart Health Study with CVD mortality outcome and complete covariate information was used. Analysis of the average SpO2 responses to respiratory events revealed a transient response from the event start that extended for four event lengths. Based on the response we developed a respiratory event related oxygen desaturation (REROD) parameter for quantifying the desaturation associated with respiratory events that is readily calculated. The performance of the parameter in predicting CVD death was assessed using an adjusted Cox proportional hazard ratio (HR) analysis and compared to other methods including hypoxic burden, T90 and ODI3.

Results

The COX analysis was adjusted for known covariates of CVD. The HR results indicate a dose-response relationship with the highest quintile providing a HR=2.0(95% C.I. 1.3–3.2).

Discussion

Our REROD metric predicts CVD mortality independent of confounding covariates and provides prediction performance superior to other hypoxemia metrics. A big advantage of our metric is its computational simplicity and reproducibility. We believe the metric is an important enabling step towards clinical methods that provide CVD risk stratification from the PSG.
O039 Differential effects of sleep deprivation and sleep restriction on error awareness
Authors: Boardman J , Bravo M , Andrillon T , Anderson C , Drummond S
Published: October 2021

Introduction

The ability to detect and subsequently correct errors is important in preventing the detrimental consequences of sleep loss. We report the first study to compare the effects of total sleep deprivation (TSD) and sleep restriction (SR) on error awareness.

Methods

Thirteen healthy adults (11F, age=26.8±3.4y) underwent a 34h TSD protocol, completing the Error Awareness Task (EAT: a combined Stroop/1-back/GoNogo task) at 4h and 27h post-wake. Twenty healthy adults (11F, age=27.4±5.3y) were studied both well-rested (WR: 9h sleep) and following SR (3 nights of 3h sleep), completing the EAT once/day (8-9h post-habitual wake). The EAT required participants to withhold responding to “nogo” stimuli and signal, via a button press, whenever they realised they made an error on these nogo trials.

Results

TSD did not significantly affect error rate (p=.712) or error awareness rate (p=.517), however, participants were slower to recognise errors after TSD (p=.004). In contrast, SR increased error rate (p<.001), decreased error awareness (p<.001), and slowed recognition of errors (p<.01).

Discussion

Three nights SR impaired the ability to recognise errors in real-time, despite a greater number of errors being made. Thus, impaired error awareness may be one mechanism underlying increased sleep loss-related accidents and errors in occupational settings, as well as at home. Interestingly, 1-night TSD did not lead to more, or impaired recognition of errors. TSD participants were slower to recognise errors, which may be problematic in safety critical settings. Technological and/or operational solutions may be needed to reduce the risk of errors going unrecognised.
O044 PROMISing questionnaires to measure sleep disturbance and impairment
Authors: Antonov A , Hamilton G
Published: October 2021

Background

Obstructive sleep apnoea (OSA) is highly prevalent in Australia with significant health and economic impacts. OSA severity as measured by Apnoea Hypopnoea Index (AHI) does not reliably predict symptom burden as measured by questionnaires such as the Epworth Sleepiness Scale (ESS) or Functional Outcomes of Sleep Questionnaire (FOSQ). Our hypothesis is that utilising the standardised, scenario-agnostic, evidence-based Patient-Reported Outcomes Information System (PROMIS) questionnaires would yield better clinical utility. The primary aim was to validate PROMIS questionnaires in detecting symptom burden of OSA and its relationship to AHI. Secondary outcomes were to investigate the relationship between PROMIS questionnaires and other commonly used measures of sleep impairment and disturbance, and the relationship between PROMIS questionnaires and surrogate markers of sleep impairment on a Polysomnogram.

Methods

Analysis of prospectively collected data from 122 adult patients referred to an Australian University and Tertiary Hospital associated sleep apnoea clinic. All adult patients who completed extensive pre-assessment questionnaires and subsequently underwent polysomnography following clinician review were included in this study. Questionnaires included: PROMIS Sleep Disturbance, Sleep Related Impairment and Cognitive Function-Abilities questionnaires, FOSQ, ESS, Insomnia Severity Index (ISI) and Hospital Anxiety and Depression Scale (HADS).

Progress to date

Data collected for all 122 participants. Preliminary analysis currently underway. Intended outcome and impact: Examine utility of the novel PROMIS scales in measuring symptom burden in patients referred for suspected OSA and its relationship to AHI. Investigate the relationship between PROMIS scales, surrogate markers of sleep impairment and other validated sleep disorder questionnaires.
P029 Home video sleep recording as a screening tool for paediatric obstructive sleep apnoea
Authors: Daniels C , Kapur N , Gauld L
Published: October 2021

Introduction

Polysomnography (PSG) remains gold standard for assessment of paediatric OSA, despite limitations. Home-based video sleep recordings offer a promising screening tool that would be relatively simple and inexpensive but have been minimally investigated. This study aims to assess the ability of short home-based video sleep recordings to predict PSG-diagnosed OSA in a population of healthy children.

Methods

Healthy children aged 1–18 years undergoing PSG to assess for OSA were recruited. Those with comorbidities likely to cause/exacerbate OSA, aside from adenotonsillar hypertrophy and obesity, were excluded. Thirty-minute video recordings of sleep shortly after sleep onset capturing the face and exposed torso were obtained. A previously validated scoring system was modified to include six parameters: snore, inspiratory noise, respiratory events, respiratory effort, mouth breathing and neck extension.

Results

We report interim results of this ongoing study. Of the 51 children meeting inclusion criteria, videos for 44 (28M, mean (SD) age 8.58 (2.96) years) were deemed satisfactory and analysed. Four (9%) children had OAHI >5 episodes/h on PSG and median Total Video Score (TVS) was 0 (IQR 0–1). TVS and OAHI >5 episodes/h on PSG showed a statistically significant association (OR 2.782, p=0.006) with area under the curve of 0.847. TVS ≥4 showed sensitivity of 75% and specificity of 100% for OAHI >5 episodes/h.

Discussion

This video scoring system, when applied to short home-based video sleep recordings, showed acceptable diagnostic accuracy for PSG-diagnosed OSA. Full data analysis will further clarify the role of this modality as a screening tool for paediatric OSA.
P042 Five-year review of a tertiary paediatric sleep service for complex patients
Authors: Griffiths A , Preston S , Adams A , Vandeleur M
Published: October 2021

Introduction

Our paediatric sleep unit commenced service for children with complex medical problems in July 2015. Service capacity includes 12 inpatient level 1 studies (two neonates) and one home study per week. FTE includes senior scientists 2.6, sleep technologists 1.7, administration 1.0, nursing 0.7 and medical 1.2. The primary aim of this study was to evaluate activity during the first 5-years. The secondary aim was to document the impact of the COVID-19 pandemic.

Methods

Sleep unit operational & diagnostic data were collected from sleep booking sheets, sleep study reports, electronic medical records. Descriptive statistics are presented.

Results

A total of 2186 sleep studies were performed (July 2015 to June 2020) with a range of 368–472 studies per annum. Overall, 61.7% were diagnostic studies, 20.8% titration studies (CPAP, oxygen, bi-level or invasive ventilation), 10% neonatal and 7.5% home studies. Between 2016–2020, the average waiting time (days) for a neonatal study was 16, a titration study was 106, a diagnostic study was 110 and a home study was 76. Further delays were caused by the COVID19 pandemic. Mean waiting time rose 229% from 108 days (Feb 2020) to 355 days (Feb 2021). Referrals for sleep studies have exceeded bed capacity since the beginning of the pandemic.

Discussion

This audit describes activity in a tertiary complex paediatric sleep service during the first 5 years. The service has struggled on current FTE and bed capacity to manage waiting times, exacerbated further by the COVID-19 pandemic. A new business and clinical model are warranted.
P060 Hypoxia-induced overexpression of Rev-Erb-alpha and NPAS2 proteins in obstructive sleep apnea patients - possible mechanism of DM2 development
Authors: Karuga F , Turkiewicz S , Ditmer M , Sochal M , Białasiewicz P , Gabryelska A
Published: October 2021

Circadian clocks are endogenous coordinators of 24-hour behavioral and molecular rhythms, which disruption may be caused by obstructive sleep apnea (OSA). It is composed of a set of genes, function as activators (CLOCK, BMAL) or repressors (PER, CRY). Neuronal PAS Domain Protein 2 (NPAS2) can substitute CLOCK in its function. Orphan nuclear receptor (Rev-Erb-α) is another protein supporting the CLOCK-BMAL1 complex, forming the loop which helps to regulate their expression. There are studies suggesting the significant influence of circadian disruption mediated via NPAS2 and Rev-Erb-α on DM2 development. The aim of the study was to determine the role of NPAS2 and Rev-Erb-α in DM2 for OSA patients.

All participants underwent polysomnography (PSG) examination. Based on apnea-hypopnea index accompanied by clinical data the recruited individuals (n=40) were assigned to one from 3 groups: OSA (severe OSA, no DM2; n=17), DM2 (severe OSA + DM2; n=7) and control group (no OSA, no DM2; n=16). Serum protein levels of Rev-Erb-α and NPAS2 were assessed with ELISA immunoassay.

Analysis between the groups revealed the statistically significant difference only in NPAS2 protein level (p=0.037). Further post-hoc analysis revealed significant differences between OSA and the control group (p=0.017). Moreover, a statistically significant correlation between AHI and NPAS2 serum protein level was observed (r=-0.478, p=0.002).

NPAS2 protein levels are associated with a number of apneas and hypopneas during the REM phase of sleep and might have a significant role in the development of OSA complications. However, further studies are needed to understand its role.
P063 Optogenetics for Obstructive Sleep Apnea
Authors: Knapman F , Burke P , Cohen M , McMullan S , Bilston L
Published: October 2021

Introduction

We propose a novel sleep apnea therapy whereby a viral vector construct induces opsin expression and therefore light sensitivity to the upper airway muscles. Pulsed light to these muscles during sleep will enhance muscle contractions resulting in airway dilation and apnea prevention. Here we investigate the therapy’s feasibility, and determine whether a muscle-specific promotor induces superior expression and light-evoked EMG responses compared to a non-specific promotor. Superiority will be determined by the strength and specificity of opsin expression as restricting expression to the tongue minimises the likelihood of immune responses and unwanted sensation, movement or pain with light application.

Methods

10 rats received an intramuscular injection of a viral vector construct to induce opsin expression in the tongue. 4 rats received a non-specific construct and 6 received a muscle-specific construct. Pulsed light was applied directly to the tongue, and genioglossus EMG activity was recorded. Confocal imaging of the brainstem and tongue quantified the strength and specificity of opsin expression.

Results

Despite the greater titer of the non-specific construct, the muscle-specific construct consistently drove stronger expression in the tongue and subsequently greater light-evoked EMG activity. Additionally, whilst the non-specific construct drove retrograde gene expression in hypoglossal motor neurons, no retrograde expression was induced by the muscle-specific construct.

Conclusions

This study provides proof-of-concept of a non-invasive optogenetic stimulation-based therapy for OSA. The superior expression and light induced EMG activity generated by the muscle-specific promotor indicates that it is the preferred promotor for future studies employing direct optogenetic stimulation of skeletal muscle.
P064 The Impact of Artefact-free Recording Time on the Diagnosis of Sleep Disordered Breathing
Authors: Knowles A , Stibalova M , Gajaweera H , Hill C , Evans H
Published: October 2021

Background

Overnight studies are used to diagnose sleep disordered breathing (SDB), however the minimum artefact-free recording time (AFRT) has not been established in children.

Aim

To determine the impact of AFRT on SDB diagnoses.

Methods

Patients attended overnight cardiorespiratory polygraphy/polysomnography, alongside pulse oximetry sleep studies. Respiratory parameter reports were generated using the first 4, 5, 6 and 7 hours of AFRT. Predetermined clinically relevant cut-off (CRCO) values were defined: Obstructive AHI (OAHI; CRCO≥2); Central Apnoea-Hypopnoea Index (CAHI; CRCO≥5); 3% Oxygen Desaturation Index (ODI3%; CRCO≥6); 4% Oxygen Desaturation Index (ODI4%; CRCO≥4). Studies crossing CRCO across different AFRTs were described as ‘Cases of Change’ (COC). Receiver operating characteristic (ROC) curves determined ranges at 4 hours which predicted COC across subsequent AFRTs.

Results

137 children (0.39–17.98 years) were consecutively recruited. Mean OAHI, CAHI, ODI3% and ODI4% were 1.54 (σ=2.66), 1.56 (σ=3.43), 5.21 (σ=6.53) and 2.77 (σ=4.42) respectively. For children achieving 7 hours AFRT (n=103), COC from 4 hours were: OAHI≥2 =9.7% (10/103); CAHI≥5 =2.9% (3/103); ODI3%≥6 =3.7% (4/109); ODI4%≥4 =1.8% (2/109). For OAHI≥2, optimal points on ROC curves for predicting COC provided a range of 0.875 (AUC= 0.733; 50% sensitivity; 93% specificity) - 3.125 (AUC= 0.968; 100% sensitivity; 81% specificity).

Conclusion

Four hours AFRT yields diagnostic results in > 90% cases when commonly used cut-off criteria are applied. For OSA, ranges at 4 hours within which diagnostic change is most likely with longer periods of AFRT are provided. Consideration should be given to repeating short studies where values lie within these ranges.
P072 The Association Between Snoring and Hearing Loss in Patients with Obstructive Sleep Apnoea
Authors: Lawton E , Jurisevic M , Hobart K , Polasek J , Fon A
Published: October 2021

Background

Snoring is the commonest symptom of OSA, occurring in 70%-95% of patients. Snoring noise in severe OSA can reach, and exceed, peaks of 80 decibels(dB). This is a noise level at which permanent hearing loss can occur.

Given the chronicity of OSA, patients may be exposed to harmful noise levels daily for many years.

Methods

All patients underwent an overnight diagnostic sleep study. Exclusion criteria included occupational noise exposure or previously diagnosed hearing loss or head injury. Calibrated and standardised Tecpel 332 Sound-Pressure-Level meters recorded quantitative sound data. In addition to standard analysis and reporting, a customised report generated snoring and sound indices during sleep time.

Participants then underwent otoscopy, tympanogram and pure tone audiometric examination.

Progress to Date

To date 14 eligible patients have been enrolled. 3/14 have completed all investigations. 3/3 have hearing loss. AHI range was 8.5–39.5 and maximum snore sound range was 78.4–98.3dB. The average snores per hour was 340.3 and mean total snores during sleep time 1741. Mean oxygen saturation nadir 87.6%.

These initial results suggest a correlation between snore noise and hearing loss. We aim to include 25 patients in this pilot study.

Intended Outcome and impact

We hypothesise a direct relationship between snoring loudness and exposure in patients with OSA, and hearing loss due to prolonged noise exposure.

Noise-induced hearing loss is irreversible, but the extent of loss may be reduced with intervention. This pilot study has the potential to benefit patients by demonstrating the effects of snoring in OSA on hearing.
P077 Reliability of the Clinical Characterization of Isolated REM Sleep Behavior Disorder
Authors: Levendowski D , Lee-Iannotti J , Shprecher D , Guevarra C , Timm P , Angel E , Mazeika G , St. Louis E
Published: October 2021

Purpose

Compare agreements between polysomnography-based (PSG) diagnosis of isolated REM-sleep-behavior-disorder (iRBD) and Non-REM-Hypertonia (NRH), a novel biomarker independently associated with synucleinopathy-related neurodegenerative diseases.

Methods

Sixteen patients with histories of dream-enactment-behavior (DEB)(women=38%; age:64.6±13.0) underwent PSG with simultaneously-recorded Sleep Profiler (SP).

Two boarded sleep neurologists independently characterized iRBD. Physician1 combined abnormal qualitative REM-sleep-without-atonia (RSWA) by submental electromyography, with video-confirmation of probably DEB. Physician2 relied solely on qualitative RSWA. SP was auto-staged, technically reviewed, and reprocessed for automated abnormal NRH detection. Kappa scores measured physician and NRH agreements.

Results

In the 14 records with REM sleep, iRBD was characterized in: Physician1=64%, Physician2=79%, NRH=71% of the records. Across the three methods, unanimous iRBD agreement occurred in 57% of the records (positive=7, negative=1).

The between-physician agreement in iRBD classifications was fair (kappa=0.32). The agreement between NRH and Physician1 was moderate (kappa=0.52) versus slight with Physician2 (kappa=0.05).

NRH comparisons to consensus physician agreement yielded one false-positive and one false-negative iRBD finding. Physician2 classified: a) iRBD in two cases that were negative by Physician1 and NRH, and b) one negative case that Physician1 and NRH characterized as iRBD. Physician1 identified one negative case that was classified iRBD by Physician2 and NRH. Additionally, NRH was abnormal in one of the two records with no REM sleep.

Discussion

NRH may assist in iRBD risk assessment, given it agreed with at least one physician in 86% of the cases and the between-physician iRBD agreement was only fair. NRH also characterized iRBD-risk in patients with insufficient REM sleep for RSWA assessment.
P080 An embedded pathway to mandibular advancement splint (MAS) construction in a tertiary hospital reduces barriers to care for low-income individuals
Authors: Lim B , Yap T , Lim M , Gikas A
Published: October 2021

Introduction

The aim of this study was to report the outcomes of patients referred within and to a tertiary hospital dental unit for subsidised construction of a MAS over a 5-year period.

Methods

Medical records of patients referred from 2015–2020 were examined for reason for referral, details of diagnosis, pathway to diagnosis, treatment, compliance, clinician-reported and lab-based outcomes and follow-up reviews.

Results

One hundred patients referred from: The Hospital Sleep Unit 40, other Tertiary Hospitals 27, Private Sleep Clinics 13, Medical GPs 10. 76 patients were confirmed health care card holders. 30 patients did not proceed for reasons of cost or poor oral health. 59 patients were newly fitted with a MAS (27F,32M), 17 severe, 21 moderate, 17 mild OSA, mean age 52.9(+13.9) years, BMI 30.2(+6.3) kg/m2, ESS 11.4(+5.3). 22 of 36 patients with serial ESS scores had excessive daytime sleepiness upon initial presentation. 15/22(68%)(p<0.005) of patients had resolution of their excessive daytime sleepiness following MAS wear. 8/15(53%) of patients had a subsequent AHI <50%. 33 patients (56%) continued MAS wear, mean follow-up time 13.8(±14.6) months with an average of 5.8(+3.0) visits. 6 were lost to follow up, 20 patients (33%) ceased MAS wear with 10(50%) of these stopping because routine dental treatment affected the device fit or discomfort later developed.

Conclusion

Subsidised expert construction of MAS embedded in a tertiary hospital is a well-utilised and effective service which reduces barriers for patients. The referrals to this service appear to be appropriate, with most patients proceeding to MAS construction.
P089 Loneliness and sleep duration among healthy older adults in Southeast Queensland, Australia
Authors: Lam J , Mann D , Pattinson C , Allan A , Smith S , Baxter J
Published: October 2021

Introduction

The relationship between sleep duration and loneliness among healthy older adults is not fully understood. Shorter sleep duration and increased variability of sleep timing (sleep onset and wake time) have recently been shown to have adverse health outcomes in younger adults. While physiological stressors associated with loneliness are likely distinct, we hypothesise that older adults who identify as lonely have reduced sleep duration and increased variability of sleep timing.

Methods

Older individuals (N=60) without significant co-morbidities were recruited via convenience sampling. Participants completed the de Jong Giervield Loneliness Scale and wore an actigraph for up to 2 weeks. Sleep metrics from actigraphy (sleep onset and wake times, and SD) were determined by algorithm assisted human scoring.

Results

Valid data was retrieved from N=37 participants (age 83±6.8 years [mean±SD]). There were no significant differences in demographics between those in the lonely (N=19) and not lonely (N=18) groupings. There was substantial heterogeneity in individual participant’s sleep metrics, both within and between groupings. The average sleep onset time was similar between groups, however lonely participants typically woke earlier resulting in slightly shorter sleep duration. Variability in sleep onset and wake times was reduced in lonely participants.

Discussion

While shorter sleep duration was expected, we did not anticipate the reduction in sleep timing variability amongst those defined as lonely; more regular sleep periods have previously been associated with better outcomes. We did not see statistically significant differences between our groups, possibly due to sample size limitations, however, the unexpected trend warrants further investigation.
P093 A Systematic Review of Adherence to Cognitive Behavioural Therapy for Insomnia (CBT-I) - Key Findings
Authors: Mellor A , Kavaliotis E , Drummond S
Published: October 2021

Introduction

Research into factors influencing adherence to CBT-I and how adherence impacts treatment outcomes remains scarce. Through a systematic review, we aimed to determine how adherence is assessed; which factors predict adherence; and which treatment outcomes are predicted by adherence.

Methods

Included publications met the following criteria: adults with insomnia; an intervention of CBT-I, including sleep restriction (SRT) and/or stimulus control (SCT); a reported measure of adherence; and written in English.

Results

Final n=103 papers. Measures assessed either global adherence or adherence to specific components of CBT-I via questionnaires, sleep diaries, interviews, or actigraphy. Most common measures were sleep diary-derived CBT-I components for therapist-led studies, and module completion for digital studies. Twenty-eight papers (27.2% of total) examined predictors of adherence. Depression, pre- and post-session sleep, psychosocial support, and dysfunctional beliefs about sleep predicted adherence. Demographic variables, other psychological comorbidities, insomnia severity, and sleep questionnaires did not predict adherence. Twenty-eight papers (27.2%) examined whether adherence predicted treatment outcomes. Neither global adherence nor adherence to any specific component of therapist-led CBT-I reliably predicted sleep outcomes. For digital CBT-I, completion of treatment modules was linked to improvements in ISI, however there were only five studies.

Conclusion

There was a high degree of heterogeneity in how adherence was measured, and in predictors and outcome variables assessed. This heterogeneity likely explains why adherence does not appear to predict treatment outcome. The field needs to develop a standardised method for assessing each specific adherence construct to fully understand the role of adherence in CBT-I.
P106 Evaluating the correlation between objective daytime sleepiness, daytime functioning and subjective sleepiness
Authors: Chee A , Lim P , Lee A , Narayan L , Zhang T , Capomolla T , Suthers B , Paech G
Published: October 2021

Introduction

Daytime sleepiness is typically assessed in clinical settings with the Multiple Sleep Latency Test (MSLT) and Maintenance of Wakefulness Test (MWT). However, these tests do not necessarily assess daytime functioning. This study aimed to assess the correlation between a 10-min Psychomotor Vigilance Test (PVT), as a measure of daytime functioning, and excessive daytime sleepiness as measured with the MSLT or MWT.

Methods

Patients attending the sleep clinic for assessments of daytime sleepiness underwent overnight polysomnography (PSG) and completed the Epworth Sleepiness Scale (ESS). The following day, patients completed four test sessions every 2h starting 1.5h after waking. Testing sessions included the Stanford Sleepiness Scale (SSS), PVT, MWT or MSLT. PVT lapses (reaction time >500ms), SSS score and sleep latencies (MSLT and MWT) were averaged within participants across sessions and regression analyses performed to assess the relationship between PVT lapses and sleepiness measures.

Results

A total of 41 patients (BMI: 33.7±8.7kg/m²; aged 44.8±17.8 years) completed the study. Of these, 22 (19 F) underwent the MSLT and 19 (2 F) underwent the MWT. PVT lapses correlated with MWT mean sleep latency (r²=0.62; p<0.001), ESS (r²= 0.19; p<0.01) and SSS (r²= 0.12; p<0.05) but not MSLT mean sleep latency (r²= 0.02; p = 0.50).

Discussion

In clinical practice, MWT and ESS are often used in conjunction to assess daytime functioning. Results suggest that the PVT could be used alongside MWT to aid clinical judgments around an individuals’ daytime functioning.
P107 Patient self-reported sleep quality, noise and light levels in a tertiary ICU: a prospective observational study
Authors: Martinez F , Seneviratne C , Chrimes A , Paech G
Published: October 2021

Introduction

Sleep is poor in intensive care units (ICU). However, there is limited research examining the causes from the patient perspective, especially in an Australian population. The current study investigated the factors that patients perceive as affecting their sleep in a major Australian tertiary ICU.

Methods

Patients (n=138, 51F; aged 58.1±16.8 years) completed a survey assessing sleep before and during their ICU stay, factors contributing to poor sleep, and factors that may have improved their sleep in the ICU. Night-time sound (16 nights) and light (28 nights) levels in rooms were also measured.

Results

Most patients reported good (38%) to very good (25%) sleep quality before their ICU stay, and poor (28%) to very poor (32%) sleep quality in the ICU. Over half (56%) reported an abnormal sleep-wake cycle and most (60%) felt as though they did not obtain sufficient sleep. Noise (54%), pain (50%) and lights (48%) were the top reasons for self-reported poor sleep. Patients felt as though their sleep would have been improved with dimmed lights (64%), a sleeping pill (57%) and closing door/blinds at night (46%). Median (IQR) overnight noise and light levels were 52.8 (51.4–54.6) dB and 39.9 (8.2–90.9) lux respectively.

Discussion

Of the top three factors that patients perceive to be the primary reasons for poor sleep, two are modifiable (noise and lights). Night-time sound levels exceed standard recommendations and light levels, while mostly low, were higher than indicated for a healthy sleep environment, suggesting that these could be modified to improve patients sleep.
P120 The Relationship Between Sleep Architecture And Cognition In Late-Life Depression
Authors: Ricciardiello A , Mowszowski L , LaMonica H , Kumfor F , Wassing R , D’Rozario A , Naismith S
Published: October 2021

Introduction

Depression in older people is associated with changes in sleep, however associations between sleep architecture and cognition have not yet been delineated. We examined sleep architecture in older people with and without depressive symptoms, and relationships with neuropsychological performance.

Methods

Adults over 50 years underwent overnight polysomnography and memory and executive function tests. Depression and controls groups were defined by a Geriatric Depression Scale-15 cut off score of 6. Sleep architectural outcomes included amount of slow wave sleep (SWS), rapid eye movement (REM) sleep, REM onset latency (ROL), NREM slow wave activity (SWA, 0.5–4 Hz), N2 sleep spindle density and REM density.

Results

The sample comprised of 71 participants with depressive symptoms and 101 controls (mean age both groups = 64, mean GDS-15 dep= 9.3, con= 1.8). There were no significant group differences in time spent in SWS, REM, REM density or SWA. Those with depressive symptoms had later ROL (p=.008) and less N2 sleep spindles (p=.03) compared to controls. A differential association was observed with less SWS being associated with poor memory recall in the depression group only (z=.342, p=0.008). No associations between sleep and executive function performance were observed.

Discussion

The link between less time in SWS and poorer memory in those with depressive symptoms could suggest that SWS is particularly pertinent for cognition in depression or that both sleep and cognition mechanisms are influenced by depressive state. Further studies are needed to determine if changes in sleep are linked with underlying neurobiological changes.
P122 Comparison of sleep estimation using Apple Watch accelerometry against polysomnography
Authors: Roomkham S , Lovell D , Szollosi I , Perrin D
Published: October 2021

Introduction

Consumer wearables offer new ways to improve our health and well-being, including sleep. Researchers are interested in consumer wearables because their widespread adoption creates the potential for larger studies than could be run with clinically validated measurement methods, as those are more expensive or less convenient. This study investigates sleep tracking using sensor data from Apple Watch in comparison to the gold standard polysomnography (PSG).

Method

We used Apple Watch accelerometer data to establish both activity and heart rate (using ballistocardiography). Thirty participants (13 female, 17 male) wore the Apple Watch on their non-dominant wrist during clinical PSG. We compared predicted sleep status at the epoch level and overall sleep parameters, taking PSG as the ground truth.

Results

Our method achieved sleep-wake classification accuracy of 84%, sensitivity of 95%, and specificity of 47%. Apple Watch overestimated total sleep time (mean+SD) by 39.4 + 57.7 mins, underestimated WASO by 45.5 + 54.6 mins and the number of awakenings by 5.0 + 6.9. We observed worse performance for participants who had PSGs exhibiting frequent respiratory events.

Discussion

Accelerometry cannot replace PSG for diagnostic purposes. However, the Apple Watch results compare favourably to previously published Actiwatch-PSG comparisons. The performance we measured suggests that Apple Watch based accelerometry could be used in longitudinal studies to gather information similar to clinically validated accelerometers, potentially on a larger scale for lower cost. Further study is needed to understand how sleep disorders affect this kind of measurement.
P127 Parliamentary Inquiry into Sleep Health Awareness in Australia: How patient-centric is the process?
Authors: Schokman A , Glozier N , Aji M , Bin Y , Kairaitis K , Cheung J
Published: October 2021

Introduction

The parliamentary inquiry into sleep health represents one of few platforms accessible to patients and their family/carers to contribute to the development of healthcare policy alongside other key stakeholder groups (i.e. healthcare professionals, organisations). Balancing diverse and sometimes divergent views of various stakeholder groups can be challenging, thus we set out to explore how patients and family/carer submissions were interpreted by the inquiry and translated into health policy recommendations.

Methods

Written submissions made to the Parliamentary Inquiry into Sleep Health Awareness in Australia 2018 by self-identified patients or family/carers with narcolepsy (n=13) were extracted and thematically analysed using the Framework Approach. Each submission was systematically coded, with emergent themes evaluated against the final policy recommendations made by the inquiry.

Results

We identified three major themes: 1) ‘Pathways to Treatment & Care’ regarding concerns around lack of healthcare and research resource allocation for narcolepsy; 2) ‘Help-seeking Experience’ related to barriers to help-seeking and accessing care; 3) ‘Patient and Family/Carers’ Lived Experience of Disease’ which encompassed the tangible effects narcolepsy has on the daily lives of patients and family/carers.

Discussion

While patients and their family/carers prioritised issues that affected their daily lives (i.e. mental health sequela, workplace accommodations), policy recommendations focused on healthcare infrastructure, funding and engagement. Increased transparency, developing processes to balance stakeholder priorities and improving accessibility to stakeholder engagement are needed if patient and family/carer needs are to be met, and for healthcare policy to remain targeted and trusted by the public.
P129 A substantial percentage of patients with Chronic Insomnia do not appreciably increase Total Sleep Time after Cognitive Behavioural Therapy for Insomnia
Authors: Scott H , Cheung J , Muench A , Ivers H , Grandner M , Lack L , Morin C , Perlis M
Published: October 2021

Introduction

Total sleep time (TST) does not exceed baseline for the majority of patients after CBT-I. However by follow-up, TST increases by almost 1 hour on average. The current study investigated the extent to which this TST improvement is common and assessed for baseline predictors of increased TST after CBT-I.

Methods

This study is an archival analysis of data from a randomised clinical trial comparing acute CBT-I to acute CBT-I plus maintenance therapy (N = 80). The percent of patients that exceeded baseline TST by ≥30 minutes was assessed at post treatment and 3, 6, 12, and 24 months following treatment. Linear mixed models were conducted to assess the effect of patient demographics (age, sex, ethnicity, marital status), and baseline Sleep Diary-reported sleep continuity and Insomnia Severity Index (ISI) scores on changes in TST.

Results

17% of patients achieved an appreciable increase in TST by treatment end, and this proportion only increased to 58% over time. Sleep Diary-reported sleep latency, wake after sleep onset, early morning awakenings, total wake time, TST, and sleep efficiency at baseline were associated with greater increases in TST after CBT-I (interaction ps < .03). Demographics and ISI scores were not significant predictors (interaction ps > .07).

Conclusion

A substantial proportion of patients do not appreciably increase TST after CBT-I, but patients with more severe sleep continuity disturbances at baseline exhibited the largest improvements. Whether all patients could increase their TST even further after CBT-I is a topic for further investigation.
P134 Modified uvulopalatopharyngoplasty and radiofrequency-in-saline tongue in the management of snoring
Authors: Lindsay B , Sideris A , Sarkis L , Lam M , Mackay S
Published: October 2021

Objective

The modified uvulopalatopharyngoplasty has not been investigated as an option in primary snoring. The aim of this study was to determine whether combined palatal and tongue surgery to enlarge and stabilize the upper airway is an effective treatment for patients with primary snoring who cannot tolerate or decline device therapy.

Study design

This was a retrospective cohort study, and included adult patients with primary snoring who underwent modified uvulopalatopharyngoplasty and radiofrequency-in-saline tongue between January 2009 and December 2020. Patients with clinically significant obstructive sleep apnoea were excluded.

Setting

Single centre study, based in New South Wales, Australia.

Methods

Primary outcome measures were the Snoring Severity Scale (a questionnaire, which indicates loudness and frequency of snoring) completed both prior to and following surgery, and the Epworth Sleepiness Scale. Mean questionnaire scores prior to and at three-month follow-up were analysed.

Results

97 adult patients underwent upper airway surgery for simple snoring, of which 68 were included in the present study (37.3 ± 11.5 years, n=17 female). The mean SSS prior to surgery was 7.0 ± 1.6 and 1.9 ± 2.3 at 3-month follow up (P < 0.0001).The mean ESS prior to surgery was 9.0 ± 4.8 and 4.1 ± 2.8 at 3-month follow up (P <0.0001).

Conclusion

The results of this study indicate that modified uvulopalatopharyngoplasty with radiofrequency-in-saline tongue is an effective treatment modality with a low complication rate. This procedure should be offered to carefully selected patients with primary snoring who have failed or declined device therapy.
P135 An audit investigating the length of time from GP referral to diagnostic polysomnography testing in an Australian tertiary center
Authors: Sriram B , Singh V , Bandaralage S , Bashford J
Published: October 2021

Introduction/Aim

Obstructive sleep apnoea is increasingly prevalent, with shorter referral to treatment time being associated with improved outcomes. Current studies describe a mean wait-time from initial referral to first outpatient review of 88 days, and from first review to diagnostic polysomnography of 123 days. This quality assurance initiative assessed how our sleep disorders centre in an Australian tertiary hospital compared to existing literature, and attempted to verify how triaging affected wait-time.

Methods

We retrospectively reviewed patients undergoing diagnostic polysomnography from 1st January 2019 to 30th June 2021. Time from initial referral to first clinic review, plus time from initial review to polysomnography, were recorded. Patient demographics and triage category of requested polysomnography were noted. Microsoft Excel was used to collect data and derive descriptive statistics.

Results

380 patients (202-male, 178-female) were included. 251 GP referrals were received. 112 patients were triaged for polysomnography within 30 days of initial review (category 4), 204 patients were triaged within 90 days (category 5), and 44 patients were non-urgent (category 6). Mean number of days between initial referral and first review was 136.13 days. Mean number of days between first review and polysomnography was 28.95 days in category 4, 93.38 days in category 5, and 180 days in category 6.

Conclusion

Time from initial referral to initial review appeared longer in this study compared to published standards. However, time from initial review to polysomnography appeared shorter. Adjusting patient triaging and/or our ability to see new referrals sooner is required to match the published standards.
P142 Head flexion has the greatest impact on OSA severity during REM sleep
Authors: Tate A , Kurup V , Shenoy B , Freakley C , Eastwood P , Walsh J , Terrill P
Published: October 2021

Introduction

Recent work has shown that head flexion has a modest worsening effect and head rotation has a modest protective effect on OSA severity. However, there is substantial variability both within and between individuals. In this analysis we aimed to identify if this variability is explained by sleep-state, BMI, age or sex.

Methods

28 participants provided informed consent and were studied using diagnostic polysomnography with the addition of a customised, accelerometry based, head posture measurement device. For each epoch during supine sleep, the sleep state (NREM/REM), average head flexion (degrees) and average head rotation (degrees) were recorded. A logistic mixed effects model was fit across all epochs with the anthropometrics (BMI, sex, age), sleep state, average head flexion and average head rotation as explanatory variables with the absence/presence of one or more respiratory event(s) as the binary outcome variable.

Results

In total, 2122 of 5369 supine sleep epochs had a respiratory event. Three participants had no supine sleep. There were significant interaction effects for flexion-rotation, BMI-rotation and REM-flexion. The REM-flexion interaction effect was the strongest interaction effect with an odds ratio per 5 degrees of head flexion in REM sleep of 1.47 (95% CI: 1.13 – 1.86).

Discussion

Head flexion related worsening of OSA severity is greatest during REM sleep. This may be explained by attenuated upper airway neuromuscular activation in REM sleep compared with NREM sleep.