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Two letters to the editor are presented in response to the article "Primary care vs specialist sleep center management of obstructive sleep apnea and daytime sleepiness and quality of life: a randomized trial" by C.L. Chal-Coetzer in a 2013 issue along with the response of the author to the same.

Single-night disease misclassification of OSA due to night-to-night variability may contribute to inconsistent findings in OSA trials. Does multinight quantification of OSA severity provide more precise estimates of associations with incident hypertension? A total of 3,831 participants without hypertension at baseline were included in simulation analyses. Included participants had ≥ 28 days of nightly apnea-hypopnea index (AHI) recordings via an under-mattress sensor and ≥ three separate BP measurements over a 3-month baseline period followed by ≥ three separate BP measurements 6 to 9 months postbaseline. Incident hypertension was defined as a mean systolic BP ≥ 140 mm Hg or a mean diastolic BP ≥ 90 mm Hg. Simulated trials (1,000) were performed, using bootstrap methods to investigate the effect of variable numbers of nights (x = 1-56 per participant) to quantify AHI and the ability to detect associations between OSA and incident hypertension via logistic regression adjusted for age, sex, and BMI. Participants were middle-aged (mean ± SD, 52 ± 12 y), mostly male (91%), and overweight (BMI, 28 ± 5 kg/m2). Single-night quantification of OSA failed to detect an association with hypertension risk in 42% of simulated trials (α =.05). Conversely, 100% of trials detected an association when AHI was quantified over ≥ 28 nights. Point estimates of hypertension risk were also 50% higher and uncertainty was five times lower during multinight vs single-night simulation trials. Multinight monitoring of OSA allows for better estimates of hypertension risk and potentially other adverse health outcomes associated with OSA. These findings have important implications for clinical care and OSA trial design. [Display omitted] [ABSTRACT FROM AUTHOR]

Background To address the growing burden of disease and long waiting lists for sleep services, a simplified two-stage model was developed and validated for identifying obstructive sleep apnoea (OSA) in primary care using a screening questionnaire followed by home sleep monitoring. Methods 157 patients aged 25-70⇔…years attending their primary care physician for any reason at six primary care clinics in rural and metropolitan regions of South Australia participated. The first 79 patients formed the development group and the next 78 patients the validation group. A screening questionnaire was developed from factors identified from sleep surveys, demographic and anthropometric data to be predictive of moderate to severe OSA. Receiver operating characteristic (ROC) curve analysis was used to validate the two-channel ApneaLink device against full polysomnography. The diagnostic accuracy of the overall two-stage model was then evaluated. Results Snoring, waist circumference, witnessed apnoeas and age were predictive of OSA and incorporated into a screening questionnaire (ROC area under curve (AUC) 0.84, 95% CI 0.75 to 0.94, p<0.001). ApneaLink oximetry with a 3% dip rate was highly predictive of OSA (AUC 0.96, 95% CI 0.91 to 1.0, p<0.001). The two-stage diagnostic model showed a sensitivity of 0.97 (95% CI 0.81 to 1.00) and specificity of 0.87 (95% CI 0.74 to 0.95) in the development group, and a sensitivity of 0.88 (95% CI 0.60 to 0.98) and specificity of 0.82 (95% CI 0.70 to 0.90) in the validation group. Conclusion A two-stage model of screening questionnaire followed by home oximetry can accurately identify patients with OSA in primary care and has the potential to expedite care for patients with this common sleep disorder. [ABSTRACT FROM AUTHOR]

Summary: Insomnia and obstructive sleep apnea commonly co‐occur (co‐morbid insomnia and sleep apnea), and their co‐occurrence has been associated with worse cardiometabolic and mental health. However, it remains unknown if people with co‐morbid insomnia and sleep apnea are at a heightened risk of incident cardiovascular events. This study used longitudinal data from the Sleep Heart Health Study (N = 5803) to investigate potential associations between co‐morbid insomnia and sleep apnea and cardiovascular disease prevalence at baseline and cardiovascular event incidence over ~11 years follow‐up. Insomnia was defined as self‐reported difficulties initiating and/or maintaining sleep AND daytime impairment. Obstructive sleep apnea was defined as an apnea–hypopnea index ≥ 15 events per hr sleep. Co‐morbid insomnia and sleep apnea was defined if both conditions were present. Data from 4160 participants were used for this analysis. The prevalence of no insomnia/obstructive sleep apnea, insomnia only, obstructive sleep apnea only and co‐morbid insomnia and sleep apnea was 53.2%, 3.1%, 39.9% and 1.9%, respectively. Co‐morbid insomnia and sleep apnea was associated with a 75% (odd ratios [95% confidence interval]; 1.75 [1.14, 2.67]) increase in likelihood of having cardiovascular disease at baseline after adjusting for pre‐specified confounders. In the unadjusted model, co‐morbid insomnia and sleep apnea was associated with a twofold increase (hazard ratio, 95% confidence interval: 2.00 [1.33, 2.99]) in risk of cardiovascular event incidence. However, after adjusting for pre‐specified covariates, co‐morbid insomnia and sleep apnea was not significantly associated with incident cardiovascular events (hazard ratio 1.38 [0.92, 2.07]). Comparable findings were obtained when an alternative definition of insomnia (difficulties initiating and/or maintaining sleep without daytime impairment) was used. [ABSTRACT FROM AUTHOR]

It is challenging to determine which patients with obstructive sleep apnea (OSA) have impaired driving ability. Vulnerability to this neurobehavioral impairment may be explained by lower brain metabolites levels involved in mitochondrial metabolism. This study compared markers of brain energy metabolism in OSA patients identified as vulnerable vs resistant to driving impairment following extended wakefulness. 44 patients with moderate‐severe OSA underwent 28hr extended wakefulness with three 90min driving simulation assessments. Using a two‐step cluster analysis, objective driving data (steering deviation and crashes) from the 2nd driving assessment (22.5 h awake) was used to categorise patients into vulnerable (poor driving, n = 21) or resistant groups (good driving, n = 23). 1H magnetic resonance spectra were acquired at baseline using two scan sequences (short echo PRESS and longer echo‐time asymmetric PRESS), focusing on key metabolites, creatine, glutamate, N‐acetylaspartate (NAA) in the hippocampus, anterior cingulate cortex and left orbito‐frontal cortex. Based on cluster analysis, the vulnerable group had impaired driving performance compared with the resistant group and had lower levels of creatine (PRESS p = ns, APRESS p = 0.039), glutamate, (PRESS p < 0.01, APRESS p < 0.01), NAA (PRESS p = 0.038, APRESS p = 0.035) exclusively in the left orbito‐frontal cortex. Adjusted analysis, higher glutamate was associated with a 21% (PRESS) and 36% (APRESS) reduced risk of vulnerable classification. Brain mitochondrial bioenergetics in the frontal brain regions are impaired in OSA patients who are vulnerable to driving impairment following sleep loss. These findings provide a potential way to identify at risk OSA phenotype when assessing fitness to drive, but this requires confirmation in larger future studies. [ABSTRACT FROM AUTHOR]

Background: The high and increasing demand for obstructive sleep apnea (OSA) care has exceeded the capacity of specialist sleep services prompting consideration of whether general practitioners could have an enhanced role in service delivery. However, little is known about the current involvement, experiences and attitudes of Australian general practitioners towards OSA. The purpose of this study was to provide an in-depth analysis of Australian general practitioners' experiences and opinions regarding their care of patients with OSA to inform the design and implementation of new general practice models of care.Methods: Purposive sampling was used to recruit participants with maximum variation in age, experience and location. Semi-structured interviews were conducted and were analysed using Thematic Analysis.Results: Three major themes were identified: (1) General practitioners are important in recognising symptoms of OSA and facilitating a diagnosis by others; (2) Inequities in access to the assessment and management of OSA; and (3) General practitioners currently have a limited role in the management of OSA.Conclusions: When consulting with patients with symptoms of OSA, general practitioners see their primary responsibility as providing a referral for diagnosis by others. General practitioners working with patients in areas of greater need, such as rural/remote areas and those of socio-economic disadvantage, demonstrated interest in being more involved in OSA management. Inequities in access to assessment and management are potential drivers for change in future models of care for OSA in general practice. [ABSTRACT FROM AUTHOR]

Background: Chronic insomnia is a highly prevalent disorder, with ten to thirty percent of Australian adults reporting chronic difficulties falling asleep and/or staying asleep such that it causes significant daytime impairment. Current Australian general practice guidelines recommend cognitive behavioural therapy for insomnia (CBTi) as first line treatment for insomnia, however research suggests that most general practice consultations for insomnia result in a prescription for hypnotic or sedative medicines. Although the first point of contact for patients experiencing symptoms of insomnia is often general practice, little is known about the current role, experiences and capacity of Australian general practitioners to manage insomnia. This study aimed to address that gap by exploring the attitudes and opinions of general practitioners regarding insomnia management, to inform the development and implementation of new models of best practice insomnia care within general practice. Methods: A descriptive, pragmatic qualitative study. Purposive sampling was used to recruit practising Australian general practitioners, varying in age, years of experience and geographic location. Semi-structured interviews were conducted, and data analysed using thematic analysis. Results: Twenty-eight general practitioners participated in the study. Three major themes were identified: 1) Responsibility for insomnia care; 2) Complexities in managing insomnia; and 3) Navigating treatment pathways. Whilst general practitioners readily accepted responsibility for the management of insomnia, provision of care was often demanding and difficult within the funding and time constraints of general practice. Patients presenting with comorbid mental health conditions and insomnia, and decision-making regarding long-term use of benzodiazepines presented challenges for general practitioners. Whilst general practitioners confidently provided sleep hygiene education to patients, their knowledge and experience of CBTi, and access and understanding of specialised referral pathways for insomnia was limited. Conclusions: General practitioners report that whilst assessing and managing insomnia can be demanding, it is an integral part of general practice. Insomnia presents complexities for general practitioners. Greater clarity about funding options, targeted education about effective insomnia treatments, and referral pathways to specialist services, such as benzodiazepine withdrawal support and psychologists, would benefit insomnia management within general practice. [ABSTRACT FROM AUTHOR]

Introduction: Nocturnal hypoxemia is associated with increased cardiovascular mortality. Here, we assess whether positive airway pressure by adaptive servo-ventilation (ASV) reduces nocturnal hypoxemic burden in patients with primary central sleep apnea (primary CSA), or heart failure related central sleep apnea (CSA-HF) and treatment emergent central sleep apnea (TECSA).Methods: Overnight oximetry data from 328 consecutive patients who underwent ASV initiation between March 2010 and May 2018 were retrospectively analyzed. Patients were stratified into three groups: primary CSA (n = 14), CSA-HF (n = 31), TECSA (n = 129). Apnea hypopnea index (AHI) and time spent below 90% SpO2 (T90) was measured. Additionally, T90 due to acute episodic desaturations (T90Desaturation) and due to non-specific and non-cyclic drifts of SpO2 (T90Non-specific) were assessed.Results: ASV reduced the AHI below 15/h in all groups. ASV treatment significantly shortened T90 in all three etiologies to a similar extent. T90Desaturation, but not T90Non-specific, was reduced by ASV across all three patient groups. AHI was identified as an independent modulator for ΔT90Desaturation upon ASV treatment (B (95% CI: -1.32 (-1.73; -0.91), p < 0.001), but not for ΔT90 or ΔT90Non-specific. Body mass index was one independent predictor of T90.Conclusions: Across different central sleep apnea etiologies, ASV reduced AHI, but nocturnal hypoxemic burden remained high due to a non-specific component of T90 not related to episodic desaturation. Whether adjunct risk factor management such as weight-loss can further reduce T90 warrants further study. [ABSTRACT FROM AUTHOR]

Background: Traditional methods for the quantification of OSA severity may not encapsulate potential relationships between hypoxemia in OSA and cardiovascular risk.Research Question: Do novel nocturnal oxygen saturation (Spo2) metrics have prognostic value in patients with OSA and high cardiovascular event risk?Study Design and Methods: We conducted post hoc analyses of the Sleep Apnea Cardiovascular Endpoints (SAVE) trial. In 2687 individuals, Cox proportional hazards models that were stratified for treatment allocation were used to determine the associations between clinical characteristics, pulse oximetry-derived metrics that were designed to quantify sustained and episodic features of hypoxemia, and cardiovascular outcomes. Metrics included oxygen desaturation index, time <90% Spo2, average Spo2 for the entire recording (mean Spo2), average Spo2 during desaturation events (desaturation Spo2), average baseline Spo2 interpolated across episodic desaturation events (baseline Spo2), episodic desaturation event duration and desaturation/resaturation-time ratio, and mean and SD of pulse rate.Results: Neither apnea-hypopnea index, oxygen desaturation index, nor any of the novel Spo2 metrics were associated with the primary SAVE composite cardiovascular outcome. Mean and baseline Spo2 were associated with heart failure (hazard ratio [HR], 0.81; 95% CI, 0.69-0.95; P = .009; and HR, 0.78; 95% CI, 0.67-0.90; P = .001, respectively) and myocardial infarction (HR, 0.86; 95% CI, 0.77-0.95; P = .003; and HR, 0.81; 95% CI, 0.73-0.90; P < .001, respectively). Desaturation duration and desaturation/resaturation time ratio, with established risk factors, predicted future heart failure (area under the curve, 0.86; 95% CI, 0.79-0.93).Interpretation: Apnea-hypopnea index and oxygen desaturation index were not associated with cardiovascular outcomes. In contrast, the pattern of oxygen desaturation was associated with heart failure and myocardial infarction. However, concomitant risk factors remained the predominant determinants for secondary cardiovascular events and thus deserve the most intensive management. [ABSTRACT FROM AUTHOR]

Falls-related hospitalization and injury rates are steadily increasing globally due to a growth in the aging population, and the associated health problems that increase risk of falls. One such associated health problem is sleep disturbances and disorders. Recent cohort studies have shown that subjectively reported poor quality sleep is associated with an increased risk of falls. Obstructive sleep apnea (OSA) is a common sleep disorder characterized by the repetitive reductions, or cessation, of airflow. Some studies have shown that OSA impairs posture/balance and gait with nocturnal hypoxemia the likely main cause. Emerging evidence suggests that treating OSA by continuous positive airway pressure (CPAP) can improve gait, but no studies to date have examined the effect of CPAP on posture/balance. The overall control of balance relies on a complex interaction between several physiological functions including vestibular, muscle, visual, and cognitive functions. We postulate that OSA impacts balance by affecting these different systems to various degrees, with the nocturnal hypoxic burden likely playing an important role. Importantly, these impairments in balance/posture and possible falls risk may be alleviated by OSA treatment. Larger mechanistic studies are needed to properly elucidate how OSA affects falls risk and future large-scale randomized control trials are needed to determine the effectiveness of OSA treatment in reducing the risk of falls. [ABSTRACT FROM AUTHOR]

Introduction: Sleep-disordered breathing (SDB) in patients with motor neurone disease (MND) is normally attributed to hypoventilation due to muscle weakness. However, we have observed different patterns of SDB among MND patients referred for non-invasive ventilation, which do not appear to be explained by respiratory muscle weakness alone. Aim: The aim of this study was to examine the characteristics of SDB in MND. Methods: This is a retrospective analysis of sleep studies (using polysomnography [PSG]), pulmonary function tests, and arterial blood gases in MND patients referred to a tertiary sleep medicine service for clinical review. Sleep apnoeas were characterised as obstructive or central, and to further characterise the nature of SDB, hypopnoeas were classified as obstructive versus central. Results: Among 13 MND patients who had a diagnostic PSG, the mean ± SD age was 68.9 ± 9.8 years, BMI 23.0 ± 4.3 kg/m2, forced vital capacity 55.7 ± 20.9% predicted, and partial pressure of CO2 (arterial blood) 52.7 ± 12.1 mm Hg. A total of 38% of patients (5/13) showed evidence of sleep hypoventilation. The total apnoea/hypopnoea index (AHI) was (median [interquartile range]) 44.4(36.2–56.4)/h, with 92% (12/13) showing an AHI >10/h, predominantly due to obstructive events, although 8% (1/13) also showed frequent central apnoea/hypopnoeas. Conclusions: Patients with MND exhibit a wide variety of SDB. The prevalence of obstructive sleep apnoea (OSA) is surprising considering the normal BMI in most patients. A dystonic tongue and increased upper-airway collapsibility might predispose these patients to OSA. The wide variety of SDB demonstrated might have implications for ventilator settings and patients' outcomes. [ABSTRACT FROM AUTHOR]

Background: Although recent evidence suggests that OSA treatment may cause weight gain, the long-term effects of CPAP on weight are not well established.Methods: This study was a post hoc analysis of the Sleep Apnea Cardiovascular Endpoints (SAVE) study, a multicenter, randomized trial of CPAP plus standard care vs standard care alone in adults with a history of cardiac or cerebrovascular events and moderate to severe OSA. Participants with weight, BMI, and neck and waist circumferences measured at baseline and during follow-up were included. Linear mixed models were used to examine sex-specific temporal differences, and a sensitivity analysis compared high CPAP adherers (≥ 4 h per night) with propensity-matched control participants.Results: A total of 2,483 adults (1,248 in the CPAP group and 1,235 in the control group) were included (mean 6.1 ± 1.5 measures of weight available). After a mean follow-up of 3.78 years, there was no difference in weight change between the CPAP and control groups, for male subjects (mean [95% CI] between-group difference, 0.07 kg [-0.40 to 0.54]; P = .773) or female subjects (mean [95% CI] between-group difference, -0.14 kg [-0.37 to 0.09]; P = .233). Similarly, there were no significant differences in BMI or other anthropometric measures. Although male participants who used CPAP ≥ 4 h per night gained slightly more weight than matched male control subjects without CPAP (mean difference, 0.38 kg [95% CI, 0.04 to 0.73]; P = .031), there were no between-group differences in other anthropometric variables, nor were there any differences between female high CPAP adherers and matched control subjects.Conclusions: Long-term CPAP use in patients with comorbid OSA and cardiovascular disease does not result in clinically significant weight change.Trial Registry: ClinicalTrials.gov; No.: NCT00738179; URL: www.clinicaltrials.gov. [ABSTRACT FROM AUTHOR]

Abstract Background Sleep-disordered breathing (SDB) is highly prevalent in patients with atrial fibrillation (AF) and its treatment can improve rhythm control. Polysomnography (PSG) is the gold standard for the diagnosis of SDB but its high cost and limited availability constrain its role as a standard SDB screening tool. We sought to assess the diagnostic utility of overnight oximetry in predicting SDB in AF patients. Methods We analyzed prospectively collected data on 439 patients with documented AF (62% paroxysmal AF) who underwent PSG. Overnight oximetry was used to determine the oxygen desaturation index (ODI, number of desaturation/h) by a novel automated computer algorithm. ODI was validated against PSG derived apnea-hypopnea index (AHI). Results The sample consisted of 69% men with a mean age of 59.9 ± 11.3 years and body mass index of 30 ± 5 kg/m2. The median AHI was 9.5 [3.6–21.0]/h and the prevalence of moderate (AHI 15–29/h) and severe SDB (AHI ≥ 30/h) was 17.3% and 16.6% respectively. The ODI was able to detect moderate-to-severe SDB (AHI ≥ 15/h; area under the receiver-operating-characteristic curve (AUC): 0.951, 95% CI: 0.929–0.972) and severe SDB (AHI ≥ 30/h; 0.932, 95% CI: 0.895–0.968) with high diagnostic accuracy. An ODI cut-off of 4.1/h resulted in a 91% sensitivity and 83% specificity in discriminating between patients with and without AHI ≥ 15/h. An ODI of 7.6/h yielded a sensitivity and specificity for AHI ≥ 30/h of 89% and 83%, respectively. Conclusions ODI derived from a simple and low-cost overnight oximetry can be used as an accessible and reliable screening tool, particularly to rule out SDB. Highlights • A new overnight oximetry algorithm detects sleep apnea in atrial fibrillation patients. • Oxygen desaturation index cut-off of 4.1/h: 91% sensitivity and 83% specificity • High negative predictive value of above 95% • Other oximetry derived parameters displayed lower diagnostic accuracy. [ABSTRACT FROM AUTHOR]

ABSTRACT Background and objective Obstructive sleep apnoea ( OSA) and insomnia coexist in clinical populations but prevalence in the community and risk factors remain largely unknown. We examined the prevalence and profile of previously undiagnosed co-morbid OSA and insomnia symptoms ( COMISA) in community-dwelling men. Methods Men ( n = 700, aged 58.5 ± 11.0 (mean ± SD) years) without a prior diagnosis of OSA completed full at-home unattended polysomnography, the Pittsburgh Sleep Quality Index and 36-item short form ( SF-36) survey (2007-2012). Insomnia symptoms included difficulty initiating/maintaining sleep in the presence of daytime fatigue ( DIMS-F). Depressive symptoms were assessed using the Beck Depression Inventory- 1A, Centre for Epidemiological Studies Depression Scale and Patient Health Questionnaire-9 ( PHQ-9) (2007-2010). Univariate ( χ2 and analysis of variance ( ANOVA)) and multiple linear regressions were used to compare data from four groups of individuals: neither disorder; previously undiagnosed OSA (apnoea-hypopnoea index ≥ 10) or DIMS-F alone; and COMISA. Results COMISA prevalence was 6.7%. Depression prevalence ( COMISA, 42.6%; DIMS-F, 21.6%; OSA, 8.4%, χ2 = 71.6, P < 0.00) and symptom scale scores (e.g. PHQ-9 mean ± SD: 16.1 ± 5.5 c.f. DIMS-F: 14.0 ± 4.9, P < 0.01 and OSA: 11.4 ± 3.0, P = 0.01) were highest in men with COMISA. In COMISA, respiratory and arousal indices were similar to those observed in OSA whilst reductions in subjective sleep and day dysfunction scores were similar to DIMS-F. After adjustment, predicted mean depression scores were all higher in DIMS-F and COMISA using linear regression (e.g. PHQ-9 β (95% CI): DIMS-F: 2.3 (1.2, 3.5); COMISA: 4.1 (3.0, 5.1)). Conclusion Men with COMISA have a greater prevalence, and severity, of depression than men with only one disorder. [ABSTRACT FROM AUTHOR]

Background: Evidence linking OSA with hypertension in population studies is conflicting. We examined longitudinal and cross-sectional associations of previously unrecognized OSA, including OSA occurring in rapid eye movement (REM) sleep, with hypertension.Methods: The Men Androgens Inflammation Lifestyle Environment and Stress (MAILES) study is a longitudinal study of community-dwelling men in Adelaide, South Australia. Biomedical assessments at baseline (2002-2006) and follow-up (2007-2010) identified hypertension (systolic ≥ 140 mm Hg and/or diastolic ≥ 90 mm Hg, or medication) and risk factors. In 2010 to 2011, 837 men without a prior diagnosis of OSA underwent full in-home unattended polysomnography of whom 739 recorded ≥ 30 min of REM sleep. Hypertension at follow-up (concomitant with OSA status) was defined as prevalent hypertension. Recent-onset hypertension was defined as hypertension at biomedical follow-up (56 months mean follow-up [range, 48-74]) in men free of hypertension at baseline.Results: Severe REM OSA (apnea hypopnea index ≥30/h) showed independent adjusted associations with prevalent (OR, 2.40, 95% CI, 1.42-4.06), and recent-onset hypertension (2.24 [1.04-4.81]). Significant associations with non-REM AHI were not seen. In men with AHI < 10, REM OSA (apnea hypopnea index) ≥ 20/h was significantly associated with prevalent hypertension (2.67 [1.33-5.38]) and the relationship with recent-onset hypertension was positive but not statistically significant (2.32 [0.79-6.84]). Similar results were seen when analyses were confined to men with non-REM AHI < 10.Conclusions: In men not considered to have OSA (AHI < 10), hypertension was associated with OSA during REM sleep. REM OSA may need consideration as an important clinical entity requiring treatment but further systematic assessment and evidence is needed. [ABSTRACT FROM AUTHOR]

Importance: Due to increasing demand for sleep services, there has been growing interest in ambulatory models of care for patients with obstructive sleep apnea. With appropriate training and simplified management tools, primary care physicians are ideally positioned to take on a greater role in diagnosis and treatment.Objective: To compare the clinical efficacy and within-trial costs of a simplified model of diagnosis and care in primary care relative to that in specialist sleep centers.Design, Setting, and Patients: A randomized, controlled, noninferiority study involving 155 patients with obstructive sleep apnea that was treated at primary care practices (n=81) in metropolitan Adelaide, 3 rural regions of South Australia or at a university hospital sleep medicine center in Adelaide, Australia (n = 74), between September 2008 and June 2010.Interventions: Primary care management of obstructive sleep apnea vs usual care in a specialist sleep center; both plans included continuous positive airway pressure, mandibular advancement splints, or conservative measures only.Main Outcome and Measures: The primary outcome was 6-month change in Epworth Sleepiness Scale (ESS) score, which ranges from 0 (no daytime sleepiness) to 24 points (high level of daytime sleepiness). The noninferiority margin was -2.0. Secondary outcomes included disease-specific and general quality of life measures, obstructive sleep apnea symptoms, adherence to using continuous positive airway pressure, patient satisfaction, and health care costs.Results: There were significant improvements in ESS scores from baseline to 6 months in both groups. In the primary care group, the mean baseline score of 12.8 decreased to 7.0 at 6 months (P < .001), and in the specialist group, the score decreased from a mean of 12.5 to 7.0 (P < .001). Primary care management was noninferior to specialist management with a mean change in ESS score of 5.8 vs 5.4 (adjusted difference, -0.13; lower bound of 1-sided 95% CI, -1.5; P = .43). There were no differences in secondary outcome measures between groups. Seventeen patients (21%) withdrew from the study in the primary care group vs 6 patients (8%) in the specialist group.Conclusions and Relevance: Among patients with obstructive sleep apnea, treatment under a primary care model compared with a specialist model did not result in worse sleepiness scores, suggesting that the 2 treatment modes may be comparable. TRIAL REGISTRATION anzctr.org.au Identifier: ACTRN12608000514303. [ABSTRACT FROM AUTHOR]

Obstructive sleep apnoea (OSA) is characterised by repetitive closure of the upper airway, repetitive oxygen desaturations and sleep fragmentation. The prevalence of adult OSA is increasing because of a worldwide increase in obesity and the ageing of populations. OSA presents with a variety of symptoms the most prominent of which are snoring and daytime tiredness. Interestingly though, a significant proportion of OSA sufferers report little or no daytime symptoms. OSA has been associated with an increased risk of cardiovascular disease, cognitive abnormalities and mental health problems. Randomised controlled trial evidence is awaited to confirm a causal relationship between OSA and these various disorders. The gold standard diagnostic investigation for OSA is overnight laboratory-based polysomnography (sleep study), however, ambulatory models of care incorporating screening questionnaires and home sleep studies have been recently evaluated and are now being incorporated into routine clinical practice. Patients with OSA are very often obese and exhibit a range of comorbidities, such as hypertension, depression and diabetes. Management, therefore, needs to be based on a multidisciplinary and holistic approach which includes lifestyle modifications. Continuous positive airway pressure (CPAP) is the first-line therapy for severe OSA. Oral appliances should be considered in patients with mild or moderate disease, or in those unable to tolerate CPAP. New, minimally invasive surgical techniques are currently being developed to achieve better patient outcomes and reduce surgical morbidity. Successful long-term management of OSA requires careful patient education, enlistment of the family's support and the adoption of self-management and patient goal-setting principles. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To assess the effects of 3months of optimal CPAP treatment on auditory event related potentials (AERP) in patients with severe obstructive sleep apnoea (OSA) compared with healthy controls. Methods: Auditory odd-ball related N1, P2, N2 and P3 AERP components were assessed in 9 severe OSA subjects and 9 healthy controls at baseline evaluation and at ∼3months follow-up in both groups, with OSA subjects treated with continuous positive air-way pressure (CPAP) during this period. Results: Severe OSA subjects showed significantly delayed, P2, N2 and P3 latencies, and significantly different P2 and P3 amplitudes compared to controls at baseline (group effect, all p <0.05). At follow-up evaluation P3 latency shortened in treated OSA patients but remained prolonged compared to controls (group by treatment interaction, p <0.05) despite high CPAP compliance (6h/night). The earlier AERP (P2 and N2) components did not change in either controls or OSA patients at follow-up and remained different in patients versus controls. Conclusions: This study demonstrates that in severe OSA patients AERP responses show minimal or no improvement and remain abnormal following 3months of optimal CPAP treatment. Significance: Persistent cortical sensory processing abnormalities despite treatment in severe OSA may have implications for daytime neurobehavioral performance and safety in OSA patients. AERP responses may help identify residual performance deficits and risks. [Copyright &y& Elsevier]

The aim of this study was to compare metropolitan on-road driving performance in patients with severe obstructive sleep apnea (OSA) and healthy age-matched controls. A driving assessor-based on-road driving test was performed at 2.00 pm in severe OSA patients and age-matched healthy controls. Main outcomemeasures included passing or failing the test, occurrence of minor traffic faults (e.g. not indicating, late braking, mirror checking) and traffic law infringements (e.g. failing to stop or give way, speeding). Compared to controls, there was no evidence of gross driving impairment or higher driving test failure rate in OSA patients. However, OSA patients demonstrated 60% more traffic law infringements (11.0 ± 1.8 versus 6.8 ± 1.0% of general driving tasks, p = 0.024), primarily reflecting repeated failure to stop at stop signs and/or traffic lights (p = 0.037). Patients with severeOSA break road laws more frequently than age-matched controls during a short city driving test,suggesting greater inattention and thus potentially higher motor vehicle accident risk. Further studies are needed to extend these early findings, which raise serious clinical and road safety concerns. [ABSTRACT FROM AUTHOR]

Background: Because of previous sleep disturbance and sleep hypoxia, patients with obstructive sleep apnea (OSA) might be more vulnerable to the effects of alcohol and sleep restriction than healthy persons.Objective: To compare the effects of sleep restriction and alcohol on driving simulator performance in patients with OSA and age-matched control participants.Design: Driving simulator assessments in 2 groups under 3 different conditions presented in random order.Setting: Adelaide Institute for Sleep Health, Sleep Laboratory, Adelaide, Australia.Participants: 38 untreated patients with OSA and 20 control participants.Measurements: Steering deviation, crashes, and braking reaction time.Intervention: Unrestricted sleep, sleep restricted to a maximum of 4 hours, and ingestion of an amount of 40% vodka calculated to achieve a blood alcohol level of 0.05 g/dL.Results: Patients with OSA demonstrated increased steering deviation compared with control participants (mean, 50.5 cm [95% CI, 46.1 to 54.9 cm] in the OSA group and 38.4 cm [CI, 32.4 to 44.4 cm] in the control group; P < 0.01) and significantly greater steering deterioration over time (group by time interaction, P = 0.02). The increase in steering deviation after sleep restriction and alcohol was approximately 40% greater in patients with OSA than in control participants (group by condition interaction, P = 0.04). Patients with OSA crashed more frequently than control participants (1 vs. 24 participants; odds ratio [OR], 25.4; P = 0.03) and crashed more frequently after sleep restriction (OR, 4.0; P < 0.01) and alcohol consumption (OR, 2.3; P = 0.02) than after normal sleep. In patients with OSA, prolonged eye closure (>2 seconds) and microsleeps (> 2 seconds of theta activity on electroencephalography) were significant crash predictors (OR, 19.2 and 7.2, respectively; P < 0.01). Braking reaction time was slower after sleep restriction than after normal sleep (mean, 1.39 [SD, 0.06] seconds vs. 1.22 [SD, 0.04] seconds; P < 0.01) but not after alcohol consumption. No group differences were found.Limitation: Simulated driving was assessed rather than on-road driving.Conclusion: Patients with OSA are more vulnerable than healthy persons to the effects of alcohol consumption and sleep restriction on various driving performance variables.Primary Funding Source: Australian National Health and Medical Research Council. [ABSTRACT FROM AUTHOR]

Our aim was to evaluate cardiac changes evoked by spontaneous and sound-induced arousals from sleep. Cardiac responses to spontaneous and auditory-induced arousals were recorded during overnight sleep studies in 28 young healthy subjects (14 males, 14 females) during non-rapid eye movement sleep. Computerized analysis was applied to assess beat-to-beat changes in heart rate, atrio-ventricular conductance, and ventricular repolarization from 30 s before to 60 s after the auditory tone. During both types of arousals, the most consistent change was the increase in the heart rate (in 62% of spontaneous and in 89% of sound-induced arousals). This was accompanied by an increase or no change in PR interval and by a decrease or no change in QT interval. The magnitude of all cardiac changes was significantly higher for tone-induced vs. spontaneous arousals (mean ± SD for heart rate: +9 ± 8 vs. + 13 ± 9 beats per mm; for PR prolongation: 14 ± 16 vs. 24 ± 22 ms; for QT shortening: -12 ± 6 vs. -20 ± 9 ms). The prevalence of transient tachycardia and PR prolongation was also significantly higher for tone-induced vs. spontaneous arousals (tachycardia: 85% vs. 57% of arousals, P < 0.001; PR prolongation: 51% vs. 25% of arousals, P < 0.001). All cardiac responses were short-lasting (10-15 s). We conclude that cardiac pacemaker region, conducting system, and ventricular myocardium may be under independent neural control. Prolongation of atrio-ventricular delay may serve to increase ventricular filling during arousal from sleep. Whether prolonged atrio-ventricular conductance associated with increased sympathetic outflow to the ventricular myocardium contributes to arrhythmogenesis during sudden arousal from sleep remains to be evaluated. [ABSTRACT FROM AUTHOR]

Prader-Willi Syndrome (PWS) is a rare genetic disorder characterized by a range of physical, psychological, and physiological abnormalities. It is also distinguished by the high prevalence of obstructive sleep apnea syndrome (OSAS), i.e., repetitive upper airway collapse during sleep resulting in hypoxia and sleep fragmentation. In non-PWS populations, OSAS is associated with a range of neurocognitive and psychosocial deficits. Importantly, these deficits are at least partly reversible following treatment. Given the findings in non-PWS populations, it is possible that OSAS may contribute to neurocognitive and psychosocial deficits in PWS. The present review examines this possibility. While acknowledging a primary contribution from the primary genetic abnormality to central neural dysfunction in PWS, we conclude that OSAS may be an important secondary contributing factor to reduced neurocognitive and psychosocial performance. Treatment of OSAS may have potential benefits in improving neurocognitive performance and behavior in PWS, but this awaits confirmatory investigation. [ABSTRACT FROM AUTHOR]

This study investigated the possible factors related to the Maintenance of Wakefulness Test (MWT) mean sleep latency. A second analysis explored the characteristics of subjects who had discrepant Epworth Sleepiness Scale (ESS) and MWT scores. A total of 151 subjects (110 mild to moderate obstructive sleep apnoea (OSA) patients and 41 control subjects) were recruited for the study. The subjects completed an overnight Polysomnography (PSG), MWT, cognitive, performance and vigilance tasks and answered self-report questionnaires on mood and sleepiness. A forward stepwise multiple regression was performed on MWT mean sleep latency. The predictor variables age ( r = 0.28), subjective sleep history for 1 week prior to MWT (sleep diary; r = 0.19) and number of >4% SaO2 Dips during the PSG ( r = −0.21) best explained the MWT results, but only accounted for 12.8% of the variance in the test. It was found that 33% of subjects had discrepant ESS and MWT scores. A new variable was created to analyse these subjects (MWT/ESS discrepancy score; MED). A forward stepwise multiple regression analysis found that depression, performance errors and sleep disordered breathing explained 13.4% of the variance in MED scores. The MWT is a complex behavioural test whose scores do not seem to have a very robust relationship with potential predictors and co-correlates. Further comprehensive study is needed if the test is to be used in a diagnostically meaningful way. [ABSTRACT FROM AUTHOR]

Background Insomnia is a prevalent and debilitating disorder commonly managed by family physicians. Insomnia guidelines recommend cognitive behavioral therapy for insomnia (CBTi) as the 'first-line' treatment. However, family physicians report limited time, knowledge, access, support, and referral options to manage patients with CBTi. Consequently, many patients with insomnia are prescribed potentially harmful and addictive sedative-hypnotic medicines (e.g. benzodiazepines). Family physicians require an insomnia management pathway that is specifically tailored to the guideline-recommendations, time demands, and capacity of family practice. Methods This mixed-methods implementation trial will test the feasibility, acceptability and effectiveness of a comprehensive digital insomnia management pathway in family practice. This novel pathway includes digital recruitment of family physicians, automatic identification of patients whose electronic medical records contain recent sedative-hypnotic prescriptions using a software management pathway and real-time notifications prompting physicians to refer patients to a well-established digital CBTi program. At least 10 family physicians and 375 patients with insomnia will be recruited. Physicians will be provided with an eBook to guide gradual sedative-hypnotic withdrawal. Feasibility and acceptability will be assessed from the perspective of patients and physicians. Effectiveness will be determined by co-primary outcomes: cessation of sedative-hypnotic use, and improvement in self-reported insomnia symptoms from baseline to 12-month follow-up. Analysis of trends in costs, cost-effectiveness and cost-utility analyses will be conducted from a societal perspective. Results and discussion This implementation trial will pave the way for future scaling-up of this insomnia management pathway to improve access to CBTi and reduce reliance on sedative-hypnotic medicines in family practice. Trial Registration: This trial was prospectively registered on the Australian and New Zealand Clinical Trials Registry (ANZCTR) (ACTRN12619001539123). • Insomnia is a common and often debilitating disorder commonly managed in family practice. • Cognitive behavioral therapy for insomnia (CBTi) is the recommended 'first line' treatment for insomnia. • Family physicians report limited time, knowledge and resources to manage insomnia with CBTi. • Consequently, most patients with insomnia are prescribed sedative-hypnotic medicines. • We describe a proposed implementation trial of a digital CBTi pathway for family practice. [ABSTRACT FROM AUTHOR]

Study Objectives: Insomnia is a highly prevalent and debilitating disorder. Cognitive behavioral therapy for insomnia (CBTi) is the recommended 'fist line' treatment, but is accessed by a minority of people with insomnia. This paper describes a system-level implementation program to improve access to CBTi in Australia to inform CBTi implementation in other locations., Methods: From 2019 to 2023, we conducted a program of work to promote sustained change in access to CBTi in Australia. Three distinct phases included 1) Scoping and mapping barriers to CBTi access, 2) Analysis and synthesis of barriers and facilitators to devise change goals, and 3) Structured promotion and coordination of change. We used a system-level approach, knowledge brokerage, and co-design, and drew on qualitative, quantitative, and implementation science methods., Results: We identified barriers to CBTi access from the perspectives of people with insomnia, primary care clinicians, and the health system. A stakeholder advisory committee was convened to co-design change goals, identify modifiable barriers, devise program logic and drive change strategies. We commenced a program to promote system-level change in CBTi access via; improved awareness and education of insomnia among primary care clinicians, self-guided interventions, and advocating to Government for additional CBTi funding mechanisms., Conclusions: This implementation program made significant progress toward improving access to CBTi in Australia. Ongoing work is required to continue this program, as long-term system-level change requires significant and sustained time, effort and resources from multiple stakeholders. This program may be used to inform CBTi implementation activities in other locations., (© 2024 American Academy of Sleep Medicine.)

Sleep disorders are common, and largely undiagnosed in early-career workers. The combination of sleep disorders and shift work has implications for mental health, workplace safety, and productivity. Early identification and management of sleep disorders is likely to be beneficial to workers, employers and the community more broadly. We assessed the feasibility and acceptability of a tailored sleep disorder screening and management pathway for individuals with future shift work requirements. Paramedic students were invited to complete an online sleep health survey, which included validated sleep disorder screening questionnaires for insomnia, obstructive sleep apnea and restless legs syndrome. Participants were able to express interest in participating in a sleep monitoring and management study. Participants at risk for a sleep disorder were identified, contacted by the study physician (RJA), notified of their sleep disorder screening results and provided with information regarding management options. Feasibility of the screening and management pathways were determined by completion of the 12 week follow-up, and ability to engage with health services for diagnostic testing or treatment. Acceptability of these pathways was assessed with a semi-structured interview on completion of the study at 12 weeks. Screening was completed in thirty participants (mean age 22.5 ± 6.7, 63% female), 17 of whom were 'at-risk' for a sleep disorder and offered a management pathway. All participants engaged with the study physician (RJA), with 16 completing the study (94% completion rate). Three participants with excessive daytime sleepiness received feedback from the study physician (RJA) and no further care required. Of the remaining 14 participants, 11 (78%) engaged with health services after speaking with the study physician (RJA). Those who engaged with diagnostic and management services reported that a structured pathway with online screening was convenient and easy to follow. Facilitating screening and management of sleep disorders in students with future shift work requirements is both feasible and acceptable. These findings can inform the development of a preventive strategy for sleep disorders and ideally, a health services feasibility trial for future shift workers., (© 2024. The Author(s).)

Breathing effort is important to quantify to understand mechanisms underlying central and obstructive sleep apnea, respiratory-related arousals, and the timing and effectiveness of invasive or noninvasive mechanically assisted ventilation. Current quantitative methods to evaluate breathing effort rely on inspiratory esophageal or epiglottic pressure swings or changes in diaphragm electromyographic (EMG) activity, where units are problematic to interpret and compare between individuals and to measured ventilation. This paper derives a novel method to quantify breathing effort in units directly comparable with measured ventilation by applying respiratory mechanics first principles to convert continuous transpulmonary pressure measurements into "attempted" airflow expected to have arisen without upper airway obstruction. The method was evaluated using data from 11 subjects undergoing overnight polysomnography, including six patients with obesity with severe obstructive sleep apnea (OSA), including one who also had frequent central events, and five healthy-weight controls. Classic respiratory mechanics showed excellent fits of airflow and volume to transpulmonary pressures during wake periods of stable unobstructed breathing (means ± SD, r 2 = 0.94 ± 0.03), with significantly higher respiratory system resistance in patients compared with healthy controls (11.2 ± 3.3 vs. 7.1 ± 1.9 cmH 2 O·L -1 ·s, P = 0.032). Subsequent estimates of attempted airflow from transpulmonary pressure changes clearly highlighted periods of acute and prolonged upper airway obstruction, including within the first few breaths following sleep onset in patients with OSA. This novel technique provides unique quantitative insights into the complex and dynamically changing interrelationships between breathing effort and achieved airflow during periods of obstructed breathing in sleep. NEW & NOTEWORTHY Ineffective breathing efforts with snoring and obstructive sleep apnea (OSA) are challenging to quantify. Measurements of esophageal or epiglottic pressure swings and diaphragm electromyography are useful, but units are problematic to interpret and compare between individuals and to measured ventilation. This paper derives a novel method that uses esophageal pressure and respiratory mechanics first principles to quantify breathing effort as "attempted" flow and volume in units directly comparable with measured airflow, volume, and ventilation.

CO 2 inhalation has been previously reported as a treatment for central sleep apnea both when associated with heart failure or where the cause is unknown. Here, we evaluated a novel CO 2 supply system using a novel open mask capable of comfortably delivering a constantly inspired fraction of CO 2 ([Formula: see text]) during sleep. We recruited 18 patients with central sleep apnea (13 patients with cardiac disease, and 5 patients idiopathic) diagnosed by diaphragm electromyogram (EMG) recordings made during overnight full polysomnography (PSG) ( night 1 ). In each case, the optimal [Formula: see text] was determined by an overnight manual titration with PSG ( night 2 ). Titration commenced at 1% CO 2 and increased by 0.2% increments until central sleep apnea (CSA) disappeared. Patients were then treated on the third night ( night 3 ) with the lowest therapeutically effective concentration of CO 2 derived from night 2 . Comparing night 1 and night 3 , both apnea-hypopnea index (AHI; 31 ± 14 vs. 6 ± 3 events/h, P < 0.01) and arousal index (22 ± 8 vs. 15 ± 8 events/h, P < 0.01) were significantly improved during CO 2 treatment. Sleep efficiency improved from 71 ± 18 to 80 ± 11%, P < 0.05, and sleep latency was shorter (23 ± 18 vs. 10 ± 10 min, P < 0.01). Heart rate was not different between night 1 and night 3 . Our data confirm the feasibility of our CO 2 delivery system and indicate that individually titrated CO 2 supplementation with a novel device including a special open mask can reduce sleep disordered breathing severity and improve sleep quality. Randomized controlled studies should now be undertaken to assess therapeutic benefit for patients with CSA. NEW & NOTEWORTHY A novel device using a special mask was developed and proved that CO 2 therapy using the device could eliminate central sleep apnea (CSA) events and improve sleep quality including reducing arousal index in patients with heart failure. The device would become a useful clinical treatment for heart failure patients with CSA.

Background: Sleep disturbance is among the most prevalent presentations in Australian general practice. Insomnia, the most common sleep disorder, is associated with impaired daytime, social and occupational function, reduced quality of life and substantially increased risk of future depression. Guidelines from Australian and international general practice, sleep and medical societies strongly recommend cognitive behavioural therapy for insomnia (CBT-i) as the first-line treatment for chronic insomnia. This is because CBT-i targets the underlying causes of insomnia, results in sustained improvements and commonly improves comorbid conditions such as depression and pain., Objective: This article aims to provide an overview of evidence-based assessment, management and referral options for insomnia in Australian general practice., Discussion: Access to brief insomnia assessment and evidenced-based treatments are becoming increasingly available to Australian general practitioners. CBT-i can be delivered through self-guided online programs or by suitably trained general practitioners and psychologists.

Continuous positive airway pressure (CPAP) is the first-line treatment for obstructive sleep apnea (OSA). Although CPAP improves symptoms (e.g., daytime sleepiness), there is a lack of high-quality evidence that CPAP prevents many long-term outcomes, including cognitive impairment, myocardial infarction, and stroke. Observational studies suggest that patients with symptoms may be particularly likely to experience these preventive benefits with CPAP, but ethical and practical concerns limited the participation of such patients in prior long-term randomized trials. As a result, there is uncertainty about the full benefits of CPAP, and resolving this uncertainty is a key priority for the field. This workshop assembled clinicians, researchers, ethicists, and patients to identify strategies to understand the causal effects of CPAP on long-term clinically important outcomes among patients with symptomatic OSA. Quasi-experimental designs can provide valuable information and are less time and resource intensive than trials. Under specific conditions and assumptions, quasi-experimental studies may be able to provide causal estimates of CPAP's effectiveness from generalizable observational cohorts. However, randomized trials represent the most reliable approach to understanding the causal effects of CPAP among patients with symptoms. Randomized trials of CPAP can ethically include patients with symptomatic OSA, as long as there is outcome-specific equipoise, adequate informed consent, and a plan to maximize safety while minimizing harm (e.g., monitoring for pathologic sleepiness). Furthermore, multiple strategies exist to ensure the generalizability and practicality of future randomized trials of CPAP. These strategies include reducing the burden of trial procedures, improving patient-centeredness, and engaging historically excluded and underserved populations.

Obstructive sleep apnea (OSA) severity can vary markedly from night-to-night. However, the impact of night-to-night variability in OSA severity on key cardiovascular outcomes such as hypertension is unknown. Thus, the primary aim of this study is to determine the effects of night-to-night variability in OSA severity on hypertension likelihood. This study uses in-home monitoring of 15,526 adults with ~180 nights per participant with an under-mattress sleep sensor device, plus ~30 repeat blood pressure measures. OSA severity is defined from the mean estimated apnea-hypopnoea index (AHI) over the ~6-month recording period for each participant. Night-to-night variability in severity is determined from the standard deviation of the estimated AHI across recording nights. Uncontrolled hypertension is defined as mean systolic blood pressure ≥140 mmHg and/or mean diastolic blood pressure ≥90 mmHg. Regression analyses are performed adjusted for age, sex, and body mass index. A total of 12,287 participants (12% female) are included in the analyses. Participants in the highest night-to-night variability quartile within each OSA severity category, have a 50-70% increase in uncontrolled hypertension likelihood versus the lowest variability quartile, independent of OSA severity. This study demonstrates that high night-to-night variability in OSA severity is a predictor of uncontrolled hypertension, independent of OSA severity. These findings have important implications for the identification of which OSA patients are most at risk of cardiovascular harm., (© 2023. The Author(s).)

Objective: The objective of this review is to identify the barriers and facilitators for the implementation of nurse-delivered models of care for chronic diseases to inform the development and evaluation of nurse-delivered models of care for chronic sleep disorders., Introduction: Increasing prevalence of sleep disorders and subsequent demand for specialist-led sleep services has prompted investigation into the management of uncomplicated sleep disorders by general practitioners. Models of sleep health care with enhanced roles for general practice nurses have been investigated within the context of randomized controlled trials; however, it is unclear how best to implement these models into clinical practice. With limited research exploring the implementation of nurse-delivered models of sleep health care within general practice, this review will examine the barriers and facilitators for the implementation of nurse-delivered models of care for chronic disease. This will inform the integration of new nurse-delivered models of care for chronic sleep disorders into routine general practice., Inclusion Criteria: Studies that report barriers and facilitators for the implementation of nurse-delivered models of care for chronic diseases for adults into a general practice setting will be included., Methods: Six databases will be searched: MEDLINE, CINAHL, Embase, Scopus, Cochrane Library, and Emcare. The search will be limited to qualitative, quantitative, and mixed methods studies. Studies will be included if they contain data that report on barriers and facilitators for implementation of nurse-delivered models of care for chronic diseases. This review will be conducted in accordance with the JBI approach to mixed methods convergent integrated systematic reviews., Systematic Review Registration Number: PROSPERO CRD42021273346., Competing Interests: The authors declare no conflict of interest., (Copyright © 2022 JBI.)

Rationale: Obstructive sleep apnea (OSA) is prevalent in patients with acute coronary syndrome (ACS) and is a cause of secondary hypertension. Objectives: To explore the long-term effects of OSA and continuous positive airway pressure (CPAP) treatment on blood pressure (BP) in patients with ACS. Methods: Post hoc analysis of the ISAACC study (Continuous Positive Airway Pressure in Patients with Acute Coronary Syndrome and Obstructive Sleep Apnea; NCT01335087) included 1,803 patients admitted for ACS. Patients with OSA (apnea-hypopnea index [AHI], ⩾15 events/h) were randomly assigned to receive either CPAP or usual care and were seen in follow-up for 1-5 years. Office BP was determined at each visit. Results: We included 596 patients without OSA, 978 patients in the usual care or poor CPAP adherence group, and 229 patients in the good CPAP adherence group. At baseline, 52% of the patients were diagnosed with hypertension. Median (25th to 75th percentile) age and body mass index were 59 (52.0 to 67.0) years and 28.2 (25.6 to 31.2) kg/m 2 , respectively. After a median (25th to 75th percentile) follow-up of 41.2 (18.3 to 59.6) months, BP changes were similar in the OSA and non-OSA groups. However, we observed an increase in BP in the third tertile of the AHI (AHI, >40 events/h), with a maximum difference in mean BP of +3.3 mm Hg at 30 months. Patients with OSA with good CPAP adherence (⩾4 h/night) reduced mean BP after 18 months compared with patients with usual care/poor CPAP adherence, with a maximum mean difference (95% confidence interval) of -4.7 (-6.7 to -2.7) mm Hg. In patients with severe OSA, we observed a maximum mean difference of -7.1 (-10.3 to -3.8) mm Hg. Conclusions: In patients with ACS, severe OSA is associated with a long-term increase in BP, which is reduced by good CPAP adherence. Clinical trial registered with www.clinicaltrials.gov (NCT01335087).

Background: Increased mortality has been reported in people with insomnia and in those with obstructive sleep apnoea (OSA). However, these conditions commonly co-occur and the combined effect of comorbid insomnia and sleep apnoea (COMISA) on mortality risk is unknown. This study used Sleep Heart Health Study (SHHS) data to assess associations between COMISA and all-cause mortality risk., Methods: Insomnia was defined as difficulties falling asleep, maintaining sleep and/or early morning awakenings from sleep ≥16 times per month, and daytime impairments. OSA was defined as an apnoea-hypopnoea index ≥15 events·h -1 . COMISA was defined if both conditions were present. Multivariable adjusted Cox proportional hazards models were used to determine the association between COMISA and all-cause mortality (n=1210) over 15 years of follow-up., Results: 5236 participants were included. 2708 (52%) did not have insomnia/OSA (reference group), 170 (3%) had insomnia-alone, 2221 (42%) had OSA-alone and 137 (3%) had COMISA. COMISA participants had a higher prevalence of hypertension (OR 2.00, 95% CI 1.39-2.90) and cardiovascular disease (CVD) (OR 1.70, 95% CI 1.11-2.61) compared with the reference group. Insomnia-alone and OSA-alone were associated with higher risk of hypertension but not CVD compared with the reference group. Compared with the reference group, COMISA was associated with a 47% (hazard ratio 1.47, 95% CI 1.06-2.07) increased risk of mortality. The association between COMISA and mortality was consistent across multiple definitions of OSA and insomnia., Conclusions: COMISA was associated with higher rates of hypertension and CVD at baseline, and an increased risk of all-cause mortality compared with no insomnia/OSA., Competing Interests: Conflict of interest: B. Lechat has nothing to disclose. Conflict of interest: S. Appleton has nothing to disclose. Conflict of interest: Y.A. Melaku has nothing to disclose. Conflict of interest: K. Hansen reports grants from the Australian Research Council, during the conduct of the study. Conflict of interest: R.D. McEvoy reports grants from the National Health and Medical Research Council, during the conduct of the study. Conflict of interest: R. Adams reports grants from The Hospital Research Foundation, National Health and Medical Research Council, ResMed Foundation, Phillips Foundation and Sleep Health Foundation, during the conduct of the study. Conflict of interest: P. Catcheside reports grants from the National Health and Medical Research Council, Defence Science and Technology, and the Flinders Foundation, outside the submitted work. Conflict of interest: L. Lack reports grants, personal fees and nonfinancial support from Re-time Pty Ltd, outside the submitted work. Conflict of interest: D.J. Eckert reports grants from the National Health and Medical Research Council of Australia, during the conduct of the study; grants and personal fees from Apnimed, and Bayer, grants from the Collaborative Research Centre (CRC-P), outside the submitted work; and has a patent “Methods for estimating key phenotypic traits for obstructive sleep apnoea and simplified clinical tools to direct targeted therapy”, PCT patent application pending. Conflict of interest: A. Sweetman has nothing to disclose., (Copyright ©The authors 2022. For reproduction rights and permissions contact permissions@ersnet.org.)

Background: The current healthcare system is challenged with a large and rising demand for obstructive sleep apnoea (OSA) services. A paradigm shift in OSA management is required to incorporate the preferences of diagnosed patients and individuals at high risk of OSA., Objectives: This study aimed to provide empirical evidence of the values and preferences of individuals diagnosed with OSA and high-risk populations regarding distinct OSA care pathway features., Methods: A discrete choice experiment was undertaken in two groups: those with a formal diagnosis of OSA (n = 421) and those undiagnosed but at high risk of having OSA (n = 1033). Participants were recruited from a large cross-sectional survey in Australia. The discrete choice experiment approach used mixed-logit regression models to determine preferences relating to eight salient features of the OSA management pathway, i.e. initial assessment provider, sleep study setting, diagnosis costs, waiting times, results interpretation, treatment options, provider of ongoing care and frequency of follow-up visits., Results: The findings indicate that all eight attributes investigated were statistically significant factors for respondents. Generally, both groups preferred low diagnostic costs, fewer follow-up visits, minimum waiting time for sleep study results and sleep specialists to recommend treatment. Management of OSA in primary care was acceptable to both groups and was the most preferred option by the high-risk group for the initial assessment, sleep study testing and ongoing care provision., Conclusions: The discrete choice experiment results offer a promising approach for systematic incorporation of patient and high-risk group preferences into the future design and delivery of care pathways for OSA management., (© 2022. The Author(s).)

Introduction: Obstructive sleep apnea (OSA) severity is based on the apnea-hypopnea index (AHI). The AHI is a simplistic measure that is inadequate for capturing disease severity and its consequences in cardiovascular diseases (CVDs). Deleterious effects of OSA have been suggested to influence the prognosis of specific endotypes of patients with acute coronary syndrome (ACS). We aim to identify respiratory polygraphy (RP) patterns that contribute to identifying the risk of recurrent cardiovascular events in patients with ACS., Methods: Post hoc analysis of the ISAACC study, including 723 patients admitted for a first ACS (NCT01335087) in which RP was performed. To identify specific RP patterns, a principal component analysis (PCA) was performed using six RP parameters: AHI, oxygen desaturation index, mean and minimum oxygen saturation (SaO 2 ), average duration of events and percentage of time with SaO 2 < 90%. An independent HypnoLaus population-based cohort was used to validate the RP components., Results: From the ISAACC study, PCA showed that two RP components accounted for 70% of the variance in the RP data. These components were validated in the HypnoLaus cohort, with two similar RP components that explained 71.3% of the variance in the RP data. The first component (component 1) was mainly characterized by low mean SaO 2 and obstructive respiratory events with severe desaturation, and the second component (component 2) was characterized by high mean SaO 2 and long-duration obstructive respiratory events without severe desaturation. In the ISAACC cohort, component 2 was associated with an increased risk of recurrent cardiovascular events in the third tertile with an adjusted hazard ratio (95% CI) of 2.44 (1.07 to 5.56; p -value = 0.03) compared to first tertile. For component 1, no significant association was found for the risk of recurrent cardiovascular events., Conclusion: A RP component, mainly characterized by intermittent hypoxemia, is associated with a high risk of recurrent cardiovascular events in patients without previous CVD who have suffered a first ACS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Zapater, Solelhac, Sánchez-de-la-Torre, Gracia-Lavedan, Benitez, Torres, De Batlle, Haba-Rubio, Berger, Abad, Duran-Cantolla, Urrutia, Mediano, Masdeu, Ordax-Carbajo, Masa, De la Peña, Mayos, Coloma, Montserrat, Chiner, Mínguez, Pascual, Cortijo, Martínez, Dalmases, Lee, McEvoy, Barbé, Heinzer and Sánchez-de-la-Torre.)

Rationale: Primary care clinicians may be well placed to play a greater role in obstructive sleep apnea (OSA) management. Objectives: To evaluate the outcomes and cost-effectiveness of sleep apnea management in primary versus specialist care, using an individual-participant data meta-analysis to determine whether age, sex, severity of OSA, and daytime sleepiness impacted outcomes. Methods: Data sources were the Cumulative Index to Nursing and Allied Health Literature (CINAHL) database, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid SP, Scopus, ProQuest, U.S. National Institutes of Health Ongoing Trials Register, and ISRCTN registry (inception until 09-25-2019). Hand searching was undertaken. Two authors independently assessed articles and included trials that randomized adults with a suspected diagnosis of sleep apnea to primary versus specialist management within the same study and reported daytime sleepiness using the Epworth Sleepiness Scale (range 0-24; >10 indicates pathological sleepiness; minimum clinically important difference 2 units) at baseline and follow-up. Results: The primary analysis combined data from 970 (100%) participants (four trials). Risk of bias was assessed (Cochrane Tool). One-stage intention-to-treat analysis showed a slightly smaller decrease in daytime sleepiness (0.8; 0.2 to 1.4), but greater reduction in diastolic blood pressure in primary care (-1.9; -3.2 to -0.6 mm Hg), with similar findings in the per-protocol analysis. Primary care-based within-trial healthcare system costs per participant were lower (-$448.51 U.S.), and quality-adjusted life years and daytime sleepiness improvements were less expensive. Similar primary outcome results were obtained for subgroups in both management settings. Conclusions: Similar outcomes in primary care at a lower cost provide strong support for implementation of primary care-based management of sleep apnea.

Rationale: Recent studies suggest that obstructive sleep apnea (OSA) severity can vary markedly from night to night, which may have important implications for diagnosis and management. Objectives: This study aimed to assess OSA prevalence from multinight in-home recordings and the impact of night-to-night variability in OSA severity on diagnostic classification in a large, global, nonrandomly selected community sample from a consumer database of people that purchased a novel, validated, under-mattress sleep analyzer. Methods: A total of 67,278 individuals aged between 18 and 90 years underwent in-home nightly monitoring over an average of approximately 170 nights per participant between July 2020 and March 2021. OSA was defined as a nightly mean apnea-hypopnea index (AHI) of more than 15 events/h. Outcomes were multinight global prevalence and likelihood of OSA misclassification from a single night's AHI value. Measurements and Main Results: More than 11.6 million nights of data were collected and analyzed. OSA global prevalence was 22.6% (95% confidence interval, 20.9-24.3%). The likelihood of misdiagnosis in people with OSA based on a single night ranged between approximately 20% and 50%. Misdiagnosis error rates decreased with increased monitoring nights (e.g., 1-night F1-score = 0.77 vs. 0.94 for 14 nights) and remained stable after 14 nights of monitoring. Conclusions: Multinight in-home monitoring using novel, noninvasive under-mattress sensor technology indicates a global prevalence of moderate to severe OSA of approximately 20%, and that approximately 20% of people diagnosed with a single-night study may be misclassified. These findings highlight the need to consider night-to-night variation in OSA diagnosis and management.

Study Objectives: The Sleep Apnea Multilevel Surgery (SAMS) trial found that modified uvulopalatopharyngoplasty with tonsillectomy (if tonsils present) combined with radiofrequency tongue ablation reduced obstructive sleep apnea (OSA) severity and daytime sleepiness in moderate-severe OSA. This study aimed to investigate mechanisms of effect on apnea-hypopnea index (AHI) reduction by assessing changes in upper airway volumes (airway space, soft palate, tongue, and intra-tongue fat)., Methods: This is a case series analysis of 43 participants of 51 randomized to the surgical arm of the SAMS trial who underwent repeat magnetic resonance imaging (MRI). Upper airway volume, length, and cross-sectional area, soft palate and tongue volumes, and tongue fat were measured. Relationships between changes in anatomical structures and AHI were assessed., Results: The participant sample was predominantly male (79%); mean ± SD age 42.7 ± 13.3 years, body mass index 30.8 ± 4.1 kg/m2, and AHI 47.0 ± 22.3 events/hour. There were no, or minor, overall volumetric changes in the airway, soft palate, total tongue, or tongue fat volume. Post-surgery there was an increase in the minimum cross-sectional area by 0.1 cm2 (95% confidence interval 0.04-0.2 cm2) in the pharyngeal airway, but not statistically significant on corrected analysis. There was no association between anatomical changes and AHI improvement., Conclusions: This contemporary multilevel upper airway surgery has been shown to be an effective OSA treatment. The current anatomical investigation suggests there are not significant post-operative volumetric changes associated with OSA improvement 6-month post-surgery. This suggests that effect on OSA improvement is achieved without notable deformation of airway volume. Reduced need for neuromuscular compensation during wake following anatomical improvement via surgery could explain the lack of measurable volume change. Further research to understand the mechanisms of action of multilevel surgery is required., Clinical Trial: This manuscript presents a planned image analysis of participants randomized to the surgical arm or the clinical trial multilevel airway surgery in patients with moderate-severe obstructive sleep apnea (OSA) who have failed medical management to assess change in OSA events and daytime sleepiness. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=266019&isReview=true%20Australian%20New%20Zealand%20Clinical%20Trials%20Registry%20ACTRN12514000338662, prospectively registered on March 31, 2014., (© Sleep Research Society 2021. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Insomnia and obstructive sleep apnea (OSA) commonly co-occur. Approximately 30-50% of patients with OSA report clinically significant insomnia symptoms, and 30-40% of patients with chronic insomnia fulfil diagnostic criteria for OSA. Compared to either insomnia or OSA alone, co-morbid insomnia and sleep apnea (COMISA) is associated with greater morbidity for patients, complex diagnostic decisions for clinicians, and reduced response to otherwise effective treatment approaches. Potential bi-directional causal relationships between the mechanisms and manifestations of insomnia and OSA could play an integral role in the development and management of COMISA. A greater understanding of these relationships is required to guide personalized diagnostic and treatment approaches for COMISA. This review summarizes the available evidence of bi-directional relationships between COMISA, including epidemiological research, case studies, single-arm treatment studies, randomized controlled treatment trials, and objective sleep study data. This evidence is integrated into a conceptual model of COMISA to help refine the understanding of potential bi-directional causal relationships between the two disorders. This theoretical framework is essential to help guide future research, improve diagnostic tools, determine novel therapeutic targets, and guide tailored sequenced and multi-faceted treatment approaches for this common, complex, and debilitating condition., Competing Interests: Conflicts of interest Financial conflicts of interest AS, LL and DMc report receiving research funding support from competitive grants from ResMed Australia; Philips Respironics USA. LL reports receiving research funding support and has shares in Re-time Pty Ltd (Adelaide, Australia). Outside the current study, DJE has a Cooperative Research Centre (CRC)-P grant (Industry partner Oventus Medical) and receives research income from Bayer and Apnimed and serves as a consultant. PC reports receiving grants from NHMRC and Defence Science and Technology outside this study. The remaining authors report no relevant financial conflicts of interest. Non-financial conflicts of interest Outside the current study DJE and PC report receiving equipment loan support from Philips. AS, LL, and DMc report receiving equipment support from Philips and ResMed. The remaining authors report no relevant non-financial conflicts of interest., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Study Objectives: The referral burden on health care systems for routine sleep disorders could be alleviated by educating primary care providers (PCPs) to diagnose and manage patients with sleep health issues. This requires effective professional education strategies and resources. This scoping review examined the literature on existing approaches to educate PCPs in sleep health management., Methods: A comprehensive literature search was conducted across 8 databases to identify citations describing the education of PCPs in diagnosing and managing sleep disorders, specifically insomnia and sleep apnea. A conceptual framework, developed from the knowledge-to-action cycle, was used to analyze citations from a knowledge translation perspective., Results: Searches identified 616 unique citations and after selection criteria were applied, 22 reports were included. Reports spanning 38 years were analyzed using components of the knowledge-to-action cycle to understand how educational interventions were designed, developed, implemented, and evaluated. Interventions involved didactic (32%), active (18%), and blended (41%) approaches, using face-to-face (27%), technology-mediated (45%), and multimodal (5%) delivery. Educational effectiveness was assessed in 73% of reports, most commonly using a pre/post questionnaire (41%)., Conclusions: While this scoping review has utility in describing existing educational interventions to upskill PCPs to diagnose and manage sleep disorders, the findings suggest that interventions are often developed without explicitly considering the evidence of best educational practice. Future interventional designs may achieve greater sustained effectiveness by considering characteristics of the target audience, the pedagogical approaches best suited to its needs, and any environmental drivers and barriers that might impede the translation of evidence into practice., Citation: King S, Damarell R, Schuwirth L, Vakulin A, Chai-Coetzer CL, McEvoy RD. Knowledge to action: a scoping review of approaches to educate primary care providers in the identification and management of routine sleep disorders. J Clin Sleep Med. 2021;17(11):2307-2324., (© 2021 American Academy of Sleep Medicine.)