Positional Sleep Apnea Among Regional and Remote Australian Population and Simulated Positional Treatment Effects

Detection of sleep apnea using smartphone-embedded inertial measurement unit

We previously demonstrated that sleep apnea (SA) can be detected using acceleration and gyroscope signals from smartwatches. This study investigated whether an inertial measurement unit (IMU) embedded in non-wristwatch devices, such as smartphones, can also detect SA when worn during sleep. During polysomnography (PSG), subjects wore an IMU-embedded GPS device (Amue Link®) and/or smartphones (Xperia® or iPhone®) on their abdomen. Triaxial acceleration and gyroscope signals were recorded overnight. Data were split into training and test groups (2:1) for each device. An algorithm was developed in the training groups to extract respiratory movements (0.13-0.70 Hz) and detect respiratory events, which were validated in the test groups. IMU-derived respiratory events showed breath-by-breath concordance with PSG apnea-hypopnea events, yielding F1 scores of 0.786, 0.821, and 0.796, respectively. Regression model derived from IMU signals correlated with PSG AHI in the test groups (r = 0.90, 0.93, and 0.96), with limits of agreement of -16.7 to 25.9, -17.4 to 22.5, and - 18.4 to 20.5. Using cutoff values from the training groups, moderate-to-severe SA (AHI ≥ 15) was identified in the test groups with AUCs of 0.95, 0.98, and 0.94 and F1 scores of 0.89, 0.96, and 0.92, respectively. IMUs embedded in non-wristwatch devices, including smartphones, can quantitatively detect SA when worn during sleep.

General Practice Sleep Scale - The "GPSS" - A proposed new tool for use in General Practice for risk assessment of Obstructive Sleep Apnoea

BACKGROUND

This pilot study investigated a new simplified OSA screening tool that could be used in primary care/GP settings - the "GPSS" tool - "General Practice Sleep Scale" and compared against common existing OSA screening tools.

METHODS

A convenience sample of patients attending the respiratory and sleep clinic in the Northern Territory of Australia were included if they completed the GPSS prior to undergoing a diagnostic polysomnography. The GPSS contained 9 questions to provide information on: sex, age, body mass index, neck circumference, snoring, witnessed apnoeas, morning tiredness, daytime sleepiness and presence of hypertension/diabetes/heart disease/depression. Presence of OSA was defined as an apnoea-hypopnoea index of ≥15/hour. The GPSS scoring was developed via log odds of regression predictions for each GPSS question upon OSA.

RESULTS

159 patients (65 % male, median age 45 years) were enrolled. A minimum score of 1 was assigned to GPSS questions, up to 5 for the strongest predictor (neck circumference). The median total GPSS score was 13 (IQR 9, 16) (maximum 22) and correlated strongly with OSA (AUC 0.812 (95 % CI 0.744, 0.881)). Categorised into low (0-7), moderate (8-13) or high risk (>13), a moderate or severe score had sensitivity 100, specificity 34.9 %. The GPSS significantly outperformed the Epworth Sleepiness Scale, Berlin questionnaire and OSA-50, and was comparable but slightly improved against the STOP-Bang.

CONCLUSIONS

The proposed GPSS tool could be of use in general practice settings. Further prospective research is warranted to test the applicability and adaptability of the GPSS tool in wider population settings.

Evaluating Positional Obstructive Sleep Apnea in Children: Prevalence, Characteristics, and Risk Factors

Purpose

This study investigates the prevalence, risk factors, and clinical characteristics of positional obstructive sleep apnea (POSA) among pediatric patients diagnosed with obstructive sleep apnea (OSA).

Patients and Methods

A total of 1,236 children aged 0 to 17 years who underwent nocturnal polysomnography (PSG) and completed the Sleep Questionnaire were included. After excluding those with an AHI <1, neurological or muscular disorders, or insufficient sleep time in specific positions, 908 patients remained: 158 with POSA and 750 with non-positional OSA (NPOSA). Propensity score matching (PSM) was applied at a 1:2 ratio, resulting in a final sample of 153 POSA and 306 NPOSA patients. Data analyses were performed using R software (version 4.2.3).

Results

The prevalence of POSA was 12.8%. After PSM, patients with POSA had a lower overall AHI (8.66 vs 10.30), REM-AHI (14.30 vs 17.40), and NREM-AHI (7.43 vs 8.77) compared to those with NPOSA. POSA patients also had a shorter total sleep time (411 vs 427 minutes), spent less time in the supine position (168 vs 225 minutes), and more time in non-supine positions (241 vs 202 minutes) than NPOSA patients. Additionally, while the supine AHI was higher in POSA patients (15.60 vs 10.30), the non-supine AHI was lower (5.00 vs 11.00) compared to NPOSA patients. The minimum oxygen saturation was slightly higher in POSA patients (0.88 vs 0.87). All differences were statistically significant (P < 0.05). Risk factors for POSA included mild OSA, allergic rhinitis, non-allergic rhinitis, and obesity.

Conclusion

The prevalence of POSA in children is lower than in adults, and its severity is less than that of NPOSA. Compared to NPOSA patients, POSA patients had significantly higher AHI during supine sleep and lower AHI during non-supine sleep. POSA patients also spent more time in non-supine positions, suggesting that avoiding supine sleep may help reduce apnea events. These findings highlight the importance of monitoring and managing sleep posture in POSA patients.

Exploring the Impact of Positional Sleep Apnea in a Turkish Population: Unveiling the Untold Story

BACKGROUND The present study aimed to investigate the risk factors associated with demographical, clinical and polysomnographic features of positional sleep apnea through different criterion of positional sleep apnea (POSA vs e-POSA) in a large patient cohort from a tertiary referral center MATERIAL AND METHODS A total of 782 OSA patients who were further diagnosed with POSA (total: n=470, e-POSA: n=204) or non-POSA (n=312) based on apnea-hypopnea index (AHI) events by overnight polysomnography were included. Demographical, clinical, and polysomnographic characteristics were recorded, while independent predictors of POSA and e-POSA were determined via linear regression analysis. RESULTS Severe OSA (AHI ≥30/h) was less common in the POSA (33.4% vs 71.5%, P<0.001) and e-POSA (9.8% vs 62.3%, P<0.001) groups than in the non-POSA and non-e-POSA groups, respectively. For POSA and e-POSA, male sex (OR 2.195, P<0.001 and OR 2.021, P=0.004, respectively), low body mass index (BMI; OR 0.932, P<0.001 and OR 0.948, P=0.006), low AHI (OR 0.954 and OR 0.902, P<0.001 for each), and less desaturation (T90%, OR 0.972 and OR 0.968, P<0.001 for each) were the common statistically significant predictors. Younger age was an independent predictor of POSA (OR 0.97, P=0.003). POSA (median 20.4 s) and e-POSA (20.5 s) groups demonstrated similar apnea-hypopnea durations (min) as the non-POSA (median 21.1 s) group. CONCLUSIONS Our findings revealed that male sex and lower values of BMI, AHI, and desaturation were common determinants of POSA and e-POSA, while younger age independently predicted POSA. POSA and e-POSA had similar clinical and polysomnographic characteristics and shared the unvaried hypoxic burden.

The Prevalence of Positional Obstructive Sleep Apnoea in a Sample of the Saudi Population

PURPOSE

Positional obstructive sleep apnoea (POSA) is of important clinical significance, as positional treatment can augment or obviate continuous positive airway pressure. This study aimed to determine the prevalence of POSA and its characteristics using different definitions.

METHODS

We retrospectively examined a cohort of patients who underwent polysomnography (PSG) between 2013 and 2019 at two sleep centres. Demographic data and PSG data were collected from 624 patients with an apnoea-hypopnea index (AHI) ≥ 5. POSA was defined using different criteria as follows: (1) AHI of at least twice as high in the supine position as in the lateral position (Cartwright' s definition). (2) A supine AHI ≥ 10 and a lateral AHI < 10 (Marklun's definition). (3) AHI of at least twice as high in the supine position than in the lateral position, with the lateral AHI not exceeding 5 (Mador's definition or Exclusive POSA; e-POSA). (4) AHI ≥ 15/h; a supine AHI ≥ twice that of the nonsupine AHI ≥ 20 min of sleep in the supine and nonsupine positions; and a nonsupine AHI < 15 (Bignold's definition).

RESULTS

The prevalence of POSA was 54% (Cartwright), 38.6% (Mador), 33.8% (Marklund) and 8.3% (Bignold). Multivariate regression analysis showed a body mass index (BMI) < 35 kg/m² was the only significant predictor of POSA. Mador's definition had the highest diagnostic yield (sensitivity 63%; specificity 100%; area under the receiver operating characteristic curve 90.2%).

CONCLUSION

POSA is common, but its prevalence depends on the definition used. Low BMI was identified as a significant predictor.

Exploring the appropriateness of prescribing practice of inhaled pharmacotherapy among Aboriginal Australians in the Top End Northern Territory of Australia: a retrospective cohort study

BACKGROUND

Aboriginal Australians are reported to have a high burden of chronic airway diseases. However, prescribing patterns and related outcomes of airway directed inhaled pharmacotherapy, (short-acting beta agonists (SABA), short-acting muscarinic antagonists (SAMA), long-acting β-agonists (LABA), long-acting muscarinic antagonists (LAMA) and inhaled corticosteroids (ICS)) among Aboriginal Australian patients with chronic airway disease have been sparsely reported in the past.

METHODS

A retrospective cohort study was conducted, using clinical, spirometry data, chest radiology, primary healthcare (PHC) presentations and hospital admission rates among Aboriginal patients identified to have been prescribed inhaled pharmacotherapy in remote and rural communities referred to the respiratory specialist service in the Top End, Northern Territory of Australia.

RESULTS

Of the 372 identified active patients, 346 (93%) had inhaled pharmacotherapy prescribed (64% female, median age 57.7 years). ICS was the most common prescription (72% of the total cohort) and was recorded to be prescribed in 76% of patients with bronchiectasis, and 80% of patients with asthma or chronic obstructive pulmonary disease (COPD). Fifty-eight percent of patients had a respiratory hospital admission and 57% had a recorded PHC presentation for a respiratory issue during the study period, with a higher rate of hospital admissions among patients prescribed ICS compared with those on SAMA/SABA or LAMA/LABA without ICS (median rate (per person per year) 0.42 vs 0.21 and 0.21 (p=0.004). Regression models demonstrated that presence of COPD or bronchiectasis alongside ICS was associated with significantly increased hospitalisation rates (1.01 admissions/person/year (95% CI 0.15 to 1.87) and 0.71 admissions/person/year (95% CI 0.23 to 1.18) against patients without COPD/bronchiectasis, respectively).

CONCLUSIONS

This study demonstrates that among Aboriginal patients with chronic airway diseases, ICS is the most common inhaled pharmacotherapy prescribed. Although LAMA/LABA and concurrent ICS use may be appropriate among patients with asthma and COPD, the use of ICS may have detrimental effects among those with underlying bronchiectasis either in isolation or concurrent COPD and bronchiectasis, potentially leading to higher hospital admission rates.

Acceptability, adaptability and adherence to CPAP therapy among Aboriginal Australians with OSA - "The A5 study"

BACKGROUND

Studies examining how Australian Aboriginal people will accept, adapt and adhere to interventions such as continuous positive airway pressure (CPAP) therapy in the management of obstructive sleep apnoea (OSA) are sparsely reported.

METHODS

In this study, clinical, demographic, polysomnographic (PSG) and CPAP data were utilised to assess and predict acceptance and adherence to CPAP therapy among adult Aboriginal Australians diagnosed to have OSA.

RESULTS

Of the 649 Aboriginal patients with OSA, 49% accepted to trial CPAP therapy. Patients who accepted to trial CPAP showed more severe OSA (65vs.35% with severe OSA), reported higher daytime sleepiness (median 10vs.9), and had a higher BMI (83vs.73% obese). Of those who accepted to trial CPAP, 62% adapted to therapy (used the device for more than 30 days). Patients who adapted had more severe OSA (71vs.54% with severe OSA), and were more likely to live in urban areas (63vs.40%). Of those who adapted, 32% were adherent to therapy. Adherent patients were more likely to live in urban areas (84vs.53%), though there was no difference in OSA severity between adherent and non-adherent patients. In multivariate models remote location and more severe OSA predicted CPAP acceptance, while urban location and more severe OSA predicted adaptation, and urban location and higher oxygen saturation nadir predicted adherence.

CONCLUSIONS

Acceptance to trial CPAP therapy was observed in the presence of symptomatic and severe OSA. However, long term adherence to CPAP therapy was significantly influenced by patients' residential location, with patients residing in remote/rural settings demonstrating significantly lower adherence rates.

Prevalence, characteristics, and respiratory arousal threshold of positional obstructive sleep apnea in China: a large scale study from Shanghai Sleep Health Study cohort

Purpose

To evaluate the prevalence, characteristics, and respiratory arousal threshold (ArTH) of Chinese patients with positional obstructive sleep apnea (POSA) according to the Cartwright Classification (CC) and Amsterdam Positional Obstructive Sleep Apnea Classification (APOC).

Methods

A large-scale cross-sectional study was conducted in our sleep center from 2007 to 2018 to analyze the clinical and polysomnography (PSG) data of Chinese POSA patients. Low ArTH was defined based on PSG indices.

Results

Of 5,748 OSA patients, 36.80% met the CC criteria, and 42.88% the APOC criteria, for POSA. The prevalence of POSA was significantly higher in women than men (40.21% and 46.52% vs. 36.13% and 42.18% for CC and APOC, respectively). Chinese POSA patients had a lower apnea hypopnea index (AHI) and lower oxygen desaturation index, shorter duration of oxygen saturation (SaO₂) < 90%, and a higher mean SaO₂ and higher lowest SaO₂ value compared to subjects with non-positional OSA (NPOSA). More than 40% of the POSA patients had a low ArTH; the proportion was extremely high in the supine-isolated-POSA (si-POSA) group and APOC I group. In multivariate logistic regression analyses, higher mean SaO₂ and lower AHI during sleep were positive predictors of POSA.

Conclusions

According to the CC and APOC criteria, more than 1/3 of our Chinese subjects with OSA had POSA. Chinese POSA patients had less severe OSA and nocturnal hypoxia. Compared to NPOSA patients, significantly more patients with POSA had a low ArTH. A low ArTH may be an important endotype in the pathogenesis of POSA, especially in patients with si-POSA and APOC I. Further studies are necessary to develop personalized management strategies for POSA patients.

Trial registration: Chinese Clinical Trial Registry; URL: http://www.chictr.org.cn; No. ChiCTR1900025714 (retrospectively registered).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02141-3.

COPD disease knowledge, self-awareness and reasons for hospital presentations among a predominately Indigenous Australian cohort: a study to explore preventable hospitalisation

Background

The prevalence of chronic obstructive pulmonary disease (COPD) is higher among Indigenous Australians than that of non-Indigenous Australians. However, no studies have investigated COPD disease awareness and knowledge among Indigenous Australians. In this study, we assessed the COPD disease awareness among Indigenous and non-Indigenous patients in the Top End Health Service region of the Northern Territory of Australia.

Methods

Of a total convenience sample of 100 adults, 86 patients consented to participate in this study over a 15-month period. A structured interview was conducted to identify participant’s level of knowledge about COPD, medications, self-management, healthcare interaction and utilisations.

Results

Most (69%) participants were Indigenous and men (52%). Indigenous patients were significantly younger (mean 56 vs 68 years p<0.001), with a higher proportion of remote residence and current smoking. COPD knowledge across the cohort was low, with 68% of Indigenous and 19% of non-Indigenous participants reporting they ‘know nothing/had never heard of COPD’. Most patients self-reported use of puffers/inhalers and were able to identify medication used; however, adherence to therapy was observed in only 18%. Shortness of breath was the most common symptom for hospital presentation (83%) and 69% of Indigenous patients reported seeking medical attention during an exacerbation. Self-management and COPD action plans were poorly implemented. A significant proportion (49%) reported ≥2 hospital admissions in the preceding 12 months. During exacerbation, although the majority of Indigenous patients were transferred to a tertiary centre from remote communities, patient’s preference was to be managed in their respective local communities.

Conclusions

Awareness and understanding of COPD are low in this cohort on several domains. Tailored and culturally appropriate initiatives for both patients and health professionals alike are required to improve COPD disease management among Indigenous population. This will not only improve quality of life but also reduce recurrent hospitalisation, healthcare cost and utilisation.

Sleep disorders among Aboriginal Australians with Machado-Joseph Disease: Quantitative results from a multiple methods study to assess the experience of people living with the disease and their caregivers

Background

Machado-Joseph Disease (MJD), or Spinocerebellar Ataxia Type 3 (SCA3), is a genetic disorder that causes progressive muscle weakness, loss of motor control, ataxia and permanent physical disability. Sleep disturbances are associated with MJD but remain poorly understood.

Objective

To investigate frequency and characteristics of sleep disorders and their association with health-related quality of life and psychosocial wellbeing for Aboriginal Australians living with MJD.

Methods

A convenience sample of MJD participants n = 24 participated in a semi-attended, ambulatory diagnostic sleep study to capture polysomnography, actigraphy and sleep diary data. Self-report measures collected were the Pittsburgh Sleep Quality Index (PSQI), STOP-BANG Questionnaire for Obstructive Sleep Apnoea (OSA), International Restless Legs Syndrome Study Group rating scale (IRLS), Kessler-5 (K5) and EuroQoL-5 Dimension (EQ5D). Caregivers (n = 22) reported EQ-5D, K5 and bed partners’ sleep behaviour (Mayo Sleep Questionnaire-Informant). Environmental factors were measured.

Results

We observed Nocturia, Sleep Related Leg Cramps, OSA, REM Behaviour Disorder, and RLS, respectively in 100%, 71%, 47%, 43%, and 33% of participants with a significant positive correlation between Body mass index (BMI) and Apnoea hypopnea index (AHI). The majority of sleep was spent in non-rapid eye movement sleep (NREM)-N2 stage (77.8% (67.7, 81.6)). Overcrowding (92%) and overnight care needs (42%) interrupted sleep. MJD participants and caregivers reported high psychological distress (K5 median 12.5 IQR 7, 16.5 & 8 IQR 6, 12 respectively).

Conclusion

Poor sleep quality and sleep disturbances are prevalent among this cohort. Disease manifestations and environmental factors are driving factors. Larger sample sizes are required to predict risk factors and confirm observed associations.

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Aboriginal People living with MJD in Australia experience numerous sleep disorders.

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Majority of sleep was spent in non-rapid eye movement sleep.

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Overcrowding and overnight care needs interrupt sleep.

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MJD participants and caregivers reported high psychological distress.

Differences in the Spirometry Parameters Between Indigenous and Non-Indigenous Patients with COPD: A Matched Control Study

Background

Comparison of spirometry parameters between Indigenous and non-Indigenous patients with underlying chronic obstructive pulmonary disease (COPD) has been sparsely reported in the past. In this study, differences in the lung function parameters (LFPs), in particular spirometry values for forced vital capacity (FVC), forced expiratory volume in one second (FEV₁) and FEV₁/FVC ratio between Indigenous and non-Indigenous patients with COPD were assessed.

Methods

In this retrospective study, Indigenous and non-Indigenous patients with a diagnosis of COPD between 2012-2020 according to spirometry criteria (ie; post-bronchodilator (BD) FEV₁/FVC < 0.7) were included. A further analysis was undertaken to compare the differences in the spirometry parameters, including lower limit of normal (LLN) values matching for age, sex, height and smoking status between these two diverse ethnic populations.

Results

A total of 240/742 (32%) Indigenous and 873/4579 (19%) non-Indigenous patients were identified to fit the criteria for COPD. Indigenous patients were significantly younger (mean difference 9.9 years), with a greater proportion of females (50% vs 33%), underweight (20% vs 8%) and current smokers (47% vs 32%). Prior to matching, Indigenous patients' post-BD percent predicted values for FVC, FEV₁, and FEV₁/FVC ratio were 17, 17%, and -2 points lower (Hedges G measure of effect size large (0.91), large (0.87), and small (0.25), respectively). Among the matched cohort (111 Indigenous and non-Indigenous), Indigenous patients LFPs remained significantly lower, with a mean difference of 16%, 16%, and -4, respectively (Hedges G large (0.94), large (0.92) and small (0.41), respectively). The differences persisted despite no significant differences in LLN values for these parameters.

Conclusion

Indigenous Australian patients with COPD display a significantly different demographic and clinical profile than non-Indigenous patients. LFPs were significantly lower, which may or may not equate to greater severity of disease in the absence of normative predictive lung function reference values specific to this population.

Sex differences in pulmonary function parameters among Indigenous Australians with and without chronic airway disease

BACKGROUND

Studies assessing normative values and sex differences in pulmonary function test parameters (PFTPs) among Indigenous populations are sparse.

METHODS

PFTPs were compared between male and female Indigenous Australian adults with and without chest radiologically proven chronic airway diseases (CADs).

RESULTS

485 adults (56% were female) with no significant difference in age, body mass index or smoking status between sexes were included. Females displayed a higher prevalence of radiology without CADs compared to males (66 vs. 52%, respectively). Among patients without CADs, after adjustment for age, stature and smoking, males displayed significantly higher absolute values of Forced Vital Capacity (FVC) (mean difference, 0.41L (0.21,0.62), p<0.001) and Forced Expiratory Volume in one second (FEV1) (mean difference 0.27L (0.07,0.47), p<0.001), with no significant difference in FEV1/FVC ratio (mean difference -0.02 (-0.06, 0.02), p = 0.174). Male and female patients with radiologically proven CADs demonstrated lower FEV1/FVC values. However, compared to females, males showed significantly greater reductions in pre- [-0.53 (-0.74, -0.32) vs. -0.29 (-0.42, -0.16), p = 0.045] and post- [-0.51 (-0.72, -0.3) vs. -0.27 (-0.39, -0.14), p = 0.049] bronchodilator FEV1.

CONCLUSIONS

There are significant sex differences in the PFTPs among Indigenous Australians. Recognising these differences may be of value in the accurate diagnosis, management, monitoring and prognostication of CADs in this population.

Comparison and outcomes of emergency department presentations with respiratory disorders among Australian indigenous and non-indigenous patients

Background

There is sparse evidence in the literature assessing emergency department presentation with respiratory disorders among Indigenous patients. The objective of this study was to evaluate the clinical characteristics and outcomes for Indigenous Australians in comparison to non-Indigenous patients presenting to Emergency Department (ED) with respiratory disorders.

Methods

In this study, two non-contiguous one-month study periods during wet (January) and dry (August) season were reported on, and differences in demographics, respiratory diagnosis, hospital admission, length of hospital stay, re-presentation to hospital after discharge and mortality between Australian Indigenous and non-Indigenous patients was assessed.

Results

There were a total of 528 respiratory ED presentations, 258 (49%) during wet and 270 (51%) in dry season, from 477 patients (52% female and 40% Indigenous). The majority of ED presentations (84%) were self-initiated, with a difference between Indigenous (80%) and non-Indigenous (88%) presentations. Indigenous presentations recorded a greater proportion of transfers from another healthcare facility compared to non-Indigenous presentations (11% vs. 1%). Less than half of presentations (42%) resulted in admission to the ward with no difference by Indigenous status. Lower respiratory tract infections were the most common cause of presentation (41%), followed by airway exacerbation (31%) which was more commonly seen among Indigenous (34%) than non-Indigenous (28%) presentations. Almost 20% of Indigenous patients reported multiple presentations to ED compared to 1% of non-Indigenous patients, though mortality on follow up did not differ (22% for both).

Conclusions

The results of this study may be an avenue to explore possibilities of implementing programs that may be helpful to reduce preventable ED presentation and recurrent hospitalisations among Indigenous population.

The positional characteristics of patients with obstructive sleep apnea: a single institute retrospective study in Japan

Obstructive sleep apnea (OSA) causes sleep-disordered breathing (SDB) due to upper airway obstruction. The severity of OSA changes with position during sleep. Patients with marked significant improvement in apnea-hypopnea index (AHI) level by sleep position change are defined as ''positional patients'' (PP), while those without improvement are defined as ''non-positional patients'' (NPP). We aimed to verify their clinical characteristics. Between May 2008 and May 2020, 237 patients with OSA were registered retrospectively and classified into two groups: PP (n = 158) and NPP (n = 79). The differences in clinical background and full-night polysomnography (PSG) between the two groups were observed. A logistic regression analysis was conducted to identify the risk factors for severe AHI (≥ 30 events/h) in the PP group. Moreover, confounding factor-adjusted sub-analysis by a propensity score matching method was performed, and the PSG results were compared between the two groups. The PP group was older than the NPP group. Furthermore, the PP group had lower body mass index (BMI) and AHI levels compared with the NPP group. The independent risk factors for severe AHI in the PP group were BMI and being in the supine position during sleep. The PP group had a significantly milder nocturnal hypoxemia despite having no significant difference in AHI levels between the two groups. The characteristics of PP were old age, low BMI, and low AHI associated with milder nocturnal hypoxemia. Moreover, they were less likely to worsen with nocturnal hypoxemia compared with NPP having similar severity.

Validity of the New "Top End Sleepiness Scale" (TESS) against the STOP-Bang Tool in Predicting Obstructive Sleep Apnoea among Indigenous Australian Adults

BACKGROUND

The validity of the newly developed sleepiness assessment tool the "Top End Sleepiness Scale" (TESS) against other established obstructive sleep apnea (OSA) screening tools has not been evaluated.

AIMS

To compare the utility and validity of the culturally safe and clinically relevant subjective daytime sleepiness assessment tool the "TESS" for use among Indigenous Australians against STOP-Bang screening tool in predicting OSA in a regional and remote Indigenous Australian cohort.

METHODS

The TESS questionnaire consisting of pictorial representations of six items representing daily activities that would induce daytime sleepiness specific for Indigenous Australians was assessed for its correlation in predicting moderate to severe OSA according to apnea hypopnea index (AHI, ≥15) against STOP-Bang screening tool.

RESULTS

Eighty Indigenous Australian patients (51% male, mean age 45.1 ± 11.5 years were included in this study with the majority (n=70, 88%) having OSA of which 65 (93%) had an AHI ≥15. AUC statistics for overall scores showed no significant difference between TESS or STOP-Bang in the prediction of OSA (p=0.16). A moderate risk score of TESS (≥3) was superior to the STOP-Bang (score 3-4) in sensitivity (84% vs. 33%) and specificity (39% vs. 30%). The sensitivity for a high risk score for the STOP-Bang (≥5) was superior to the TESS (≥8) (60% vs. 33%), though specificity was comparable (83% vs. 91% respectively).

CONCLUSIONS

The TESS screening tool could be a useful standalone or could be adopted alongside STOP-Bang OSA screening tools in the clinical assessment of sleep disorders among Indigenous Australians. This article is protected by copyright. All rights reserved.

The Effects of Inhaled Airway Directed Pharmacotherapy on Decline in Lung Function Parameters Among Indigenous Australian Adults With and Without Underlying Airway Disease

BACKGROUND

The trajectory of lung function decline among Indigenous patients with or without underlying chronic airway disease (COPD and concomitant bronchiectasis) and with use of inhaled pharmacotherapy, including inhaled corticosteroids (ICS), has not been reported in the past.

METHODS

Adult Indigenous Australian patients identified to have undergone at least two or more lung function tests (LFTs) between 2012 and 2020 were assessed for changes in the lung function parameters (LFPs) between the first and last recorded LFTs.

RESULTS

Of the total 1350 patients identified to have undergone LFTs, 965 were assessed to fulfil session quality, 115 (n=58 females) were eligible to be included with two or more LFTs. Among the 115 patients, 49% showed radiological evidence of airway diseases, and 77% were on airway directed inhaled pharmacotherapy. Median time between LFTs was 1.5 years (IQR 0.86,5.85), with no significant differences in LFPs noted between first and last LFT. Overall rate of change (mL/year) showed considerable variation for FVC (median -37.55 mL/year [IQR -159.88,92.67]) and FEV1 (-18.74 mL/year [-102.49,71.44]) with minimal change in FEV1/FVC (0.00 ratio/year [-0.03,0.01]). When stratified by inhaled pharmacotherapy group, however, patients using ICS showed significantly greater rate of FEV1 decline (-48.64 mL/year [-110.18,62.5]) compared to those using pharmacotherapy with no ICS (15.46 mL/year [-73.5,74.62]) and those using no pharmacotherapy (-5.76 mL/year [-63.19,67.34]) (p=0.022). Additionally, a greater proportion of these patients reached the threshold for excessive FEV1 decline (64%) compared to those using pharmacotherapy without ICS (44%) and those using no pharmacotherapy (52%).

CONCLUSION

Decline in LFPs occurs commonly among adult Indigenous population, especially, excessive so among those using inhaled pharmacotherapy containing ICS.

The Top End Sleepiness Scale (TESS): A New Tool to Assess Subjective Daytime Sleepiness Among Indigenous Australian Adults

PURPOSE

To illustrate the utility of a newly developed culturally safe and clinically relevant subjective daytime sleepiness assessment tool "Top End Sleepiness Scale" (TESS) for use among Indigenous Australians.

PATIENTS AND METHODS

The TESS questionnaire consists of pictorial representations of 6 items representing daily activities that would induce daytime sleepiness specific for Indigenous Australians living in the regional and remote Australia. Consecutive adult Indigenous patients who consented to pilot the TESS questionnaire prior to undergoing a diagnostic polysomnography (PSG) at the Top End Health Service region, Northern Territory of Australia were assessed. The TESS questionnaire was evaluated for its correlation in predicting obstructive sleep apnea (OSA) according to apnea-hypopnea index.

RESULTS

Eighty-two patients were included. The majority (70%) had moderate to severe OSA (AHI ≥15). Patients were aged in their mid-40's (45.47 95% CI (42.9, 48.05)) with a tendency to obesity (median BMI 33.67 IQR 30.86, 38.95) and a high prevalence of chronic conditions (72%) (hypertension, diabetes or heart disease). The TESS showed high internal consistency (Split half Spearman correlation=0.71, Cronbach's α =0.81), and a cut-off value ≥3 resulted in sensitivity 84%, specificity 38%. Comparison of area under the curve for TESS to Epworth Sleepiness Scale (ESS) in this sample showed the TESS to have greater sensitivity and specificity overall, which approached significance (p=0.072) when cut-off values of ≥3 and ≥8 (TESS & ESS respectively) were used. The sensitivity and specificity for TESS was also comparable to the other currently used questionnaires, such as the Berlin Questionnaire, STOP-BANG and OSA 50.

CONCLUSION

Currently, there are no subjective daytime sleepiness assessment toll available specifically for Indigenous population. The proposed TESS sleepiness screening tool represented in this study can potentially complement or adopted alongside other existing questionnaire, which may offer greater utility in the assessment of sleep disorders among Indigenous people.