Excessive daytime sleepiness is associated with relative delta frequency power among patients with mild OSA.

Background: Excessive daytime sleepiness (EDS) is a cause of low quality of life among obstructive sleep apnoea (OSA) patients. Current methods of assessing and predicting EDS are limited due to time constraints or differences in subjective experience and scoring. Electroencephalogram (EEG) power spectral densities (PSDs) have shown differences between OSA and non-OSA patients, and fatigued and non-fatigued patients. Therefore, polysomnographic EEG PSDs may be useful to assess the extent of EDS among patients with OSA. Methods: Patients presenting to Israel Loewenstein hospital reporting daytime sleepiness who recorded mild OSA on polysomnography and undertook a multiple sleep latency test. Alpha, beta, and delta relative powers were assessed between patients categorized as non-sleepy (mean sleep latency (MSL) ≥10 min) and sleepy (MSL <10 min). Results: 139 patients (74% male) were included for analysis. 73 (53%) were categorized as sleepy (median MSL 6.5 min). There were no significant differences in demographics or polysomnographic parameters between sleepy and non-sleepy groups. In multivariate analysis, increasing relative delta frequency power was associated with increased odds of sleepiness (OR 1.025 (95% CI 1.024-1.026)), while relative alpha and beta powers were associated with decreased odds. The effect size of delta PSD on sleepiness was significantly greater than that of either alpha or beta frequencies. Conclusion: Delta PSD during polysomnography is significantly associated with a greater degree of objective daytime sleepiness among patients with mild OSA. Further research is needed to corroborate our findings and identify the direction of potential causal correlation between delta PSD and EDS.

Nocturnal oxygen resaturation parameters are associated with cardiorespiratory comorbidities.

BACKGROUND: There are strong associations between oxygen desaturations and cardiovascular outcomes. Additionally, oxygen resaturation rates are linked to excessive daytime sleepiness independent of oxygen desaturation severity. No studies have yet looked at the independent effects of comorbidities or medications on resaturation parameters. METHODS: The Sleep Heart Health Study data was utilised to derive oxygen saturation parameters from 5804 participants. Participants with a history of comorbidities or medication usage were compared against healthy participants with no comorbidity/medication history. RESULTS: 4293 participants (50.4% female, median age 64 years) were included in the analysis. Females recorded significantly faster resaturation rates (mean 0.61%/s) than males (mean 0.57%/s, p < 0.001), regardless of comorbidities. After adjusting for demographics, sleep parameters, and desaturation parameters, resaturation rate was reduced with hypertension (-0.09 (95% CI -0.16, -0.03)), myocardial infarction (-0.13 (95% CI -0.21, -0.04)) and heart failure (-0.19 (95% CI -0.33, -0.05)), or when using anti-hypertensives (-0.10 (95% CI -0.17, -0.03)), mental health medications (-0.18 (95% CI -0.27, -0.08)) or anticoagulants (-0.41 (95% CI -0.56, -0.26)). Desaturation to Resaturation ratio for duration was decreased with mental health (-0.21 (95% CI -0.34, -0.08)) or diabetic medications (-0.24 (95% CI -0.41, -0.07)), and desaturation to resaturation ratio for area decreased with heart failure (-0.25 (95% CI -0.42, -0.08)). CONCLUSIONS: Comorbidities and medications significantly affect nocturnal resaturation parameters, independent of desaturation parameters. However, the causal relationship remains unclear. Further research can enhance our knowledge and develop more precise and safer interventions for individuals affected by certain comorbidities.

Significance of lung nodules detected on chest CT among adult Aboriginal Australians - a retrospective descriptive study.

INTRODUCTION: There are limited data on chest computed tomography (CT) findings in the assessment of lung nodules among adult Aboriginal Australians. In this retrospective study, we assessed lung nodules among a group of adult Aboriginal Australians in the Northern Territory of Australia. METHODS: Patients who underwent at least two chest CT scans between 2012 and 2020 among those referred to undergo lung function testing (spirometry) were included. Chest CT scans were assessed for the number, location, size and morphological characteristics of lung nodules. RESULTS: Of the 402 chest CTs assessed, 75 patients (18.7%) had lung nodules, and 57 patients were included in the final analysis with at least two CT scans available for assessment over a median follow-up of 87 weeks. Most patients (68%) were women, with a median age of 58 years and smoking history in 83%. The majority recorded only a single nodule 43 (74%). Six patients (10%) were diagnosed with malignancy, five with primary lung cancer and one with metastatic thyroid cancer. Of the 51 (90%) patients assessed to be benign, 64 nodules were identified, of which 25 (39%) resolved, 38 (59%) remained stable and one (1.8%) enlarged on follow-up. Nodules among patients with malignancy were typically initially larger and enlarged over time, had spiculated margins and were solid, showing no specific lobar predilection. CONCLUSIONS: Most lung nodules in Aboriginal Australians are likely to be benign. However, a proportion could be malignant. Further prospective studies are required for prognostication and monitoring of lung nodules in this population.

Hospital admission rates and related outcomes among adult Aboriginal australians with bronchiectasis - a ten-year retrospective cohort study.

BACKGROUND: This study assessed hospitalisation frequency and related clinical outcomes among adult Aboriginal Australians with bronchiectasis over a ten-year study period. METHOD: This retrospective study included patients aged ≥ 18 years diagnosed with bronchiectasis between 2011 and 2020 in the Top End, Northern Territory of Australia. Hospital admissions restricted to respiratory conditions (International Classification of Diseases (ICD) code J) and relevant clinical parameters were assessed and compared between those with and without hospital admissions. RESULTS: Of the 459 patients diagnosed to have bronchiectasis, 398 (87%) recorded at least one respiratory related (ICD-J code) hospitalisation during the 10-year window. In comparison to patients with a recorded hospitalisation against those without-hospitalised patients were older (median 57 vs 53 years), predominantly females (54 vs 46%), had lower body mass index (23 vs 26 kg/m2) and had greater concurrent presence of chronic obstructive pulmonary disease (COPD) (88 vs 47%), including demonstrating lower spirometry values (forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) (median FVC 49 vs 63% & FEV1 36 vs 55% respectively)). The total hospitalisations accounted for 3,123 admissions (median 4 per patient (IQR 2, 10)), at a median rate of 1 /year (IQR 0.5, 2.2) with a median length of 3 days (IQR 1, 6). Bronchiectasis along with COPD with lower respiratory tract infection (ICD code-J44) was the most common primary diagnosis code, accounting for 56% of presentations and 46% of days in hospital, which was also higher for patients using inhaled corticosteroids (81 vs 52%, p = 0.007). A total of 114 (29%) patients were recorded to have had an ICU admission, with a higher rate, including longer hospital stay among those patients with bronchiectasis and respiratory failure related presentations (32/35, 91%). In multivariate regression model, concurrent presence of COPD or asthma alongside bronchiectasis was associated with shorter times between subsequent hospitalisations (-423 days, p = 0.007 & -119 days, p = 0.02 respectively). CONCLUSION: Hospitalisation rates among adult Aboriginal Australians with bronchiectasis are high. Future interventions are required to explore avenues to reduce the overall morbidity associated with bronchiectasis among Aboriginal Australians.

Bronchiectasis among Indigenous adults in the Top End of the Northern Territory, 2011-2020: a retrospective cohort study.

OBJECTIVES: To assess the prevalence of bronchiectasis among Aboriginal and Torres Strait Islander (Indigenous) adults in the Top End of the Northern Territory, and mortality among Indigenous adults with bronchiectasis. STUDY DESIGN: Retrospective cohort study. SETTING, PARTICIPANTS: Aboriginal and Torres Strait Islander adults (18 years or older) living in the Top End Health Service region of the NT in whom bronchiectasis was confirmed by chest computed tomography (CT) during 1 January 2011 - 31 December 2020. MAIN OUTCOME MEASURES: Prevalence of bronchiectasis, and all-cause mortality among Indigenous adults with CT-confirmed bronchiectasis - overall, by sex, and by health district - based on 2011 population numbers (census data). RESULTS: A total of 23 722 Indigenous adults lived in the Top End Health Service region in 2011; during 2011-2020, 459 people received chest CT-confirmed diagnoses of bronchiectasis. Their median age was 47.5 years (interquartile range [IQR], 39.9-56.8 years), 254 were women (55.3%), and 425 lived in areas classified as remote (93.0%). The estimated prevalence of bronchiectasis was 19.4 per 1000 residents (20.6 per 1000 women; 18.0 per 1000 men). The age-adjusted prevalence of bronchiectasis was 5.0 (95% CI, 1.4-8.5) cases per 1000 people in the Darwin Urban health area, and 18-36 cases per 1000 people in the three non-urban health areas. By 30 April 2023, 195 people with bronchiectasis had died (42.5%), at a median age of 60.3 years (IQR, 50.3-68.9 years). CONCLUSION: The prevalence of bronchiectasis burden among Indigenous adults in the Top End of the NT is high, but differed by health district, as is all-cause mortality among adults with bronchiectasis. The socio-demographic and other factors that contribute to the high prevalence of bronchiectasis among Indigenous Australians should be investigated so that interventions for reducing its burden can be developed.

Cystic lung disease in adult Indigenous Australians in the Northern Territory of Australia.

INTRODUCTION: Indigenous Australians have a high prevalence of chronic lung diseases. However, no previous studies have reported on cystic lung disease in an Indigenous patient cohort. METHODS: This report describes 20 adult Indigenous patients noted to have incidental lung cysts on chest computed tomography (CT) while being referred to undergo lung function tests in the Northern Territory of Australia. RESULTS: Of the total 20 Indigenous patients demonstrating presence of pulmonary cysts on chest CT scan, 13/20 (65%) were males with a mean age of 49.9 years (range 24-74 years), with no significant difference in age between males and females. The majority reported a smoking history and spirometry demonstrated moderate reduction in lung function parameters. While there was no pattern in the size or location of cysts, most demonstrated multiple cysts (55% had ≥5 cysts) with bilateral involvement (65%), alongside a range of concurrent pulmonary radiological abnormalities. The aetiology for lung cysts was largely unknown. CONCLUSION: This is the first report to illustrate cystic lung disease within an Indigenous population. Further radiology studies are required to investigate the causes and prognostications of cystic lung disease in Indigenous patients.

Significance and prognostication of mediastinal lymph node enlargement on chest computed tomography among adult Indigenous Australians.

INTRODUCTION: There is a lack of data on chest computed tomography (CT) findings on mediastinal lymph node enlargement (MLE), including normal size threshold of less than 10 or 15 mm for MLE among Indigenous Australians. In this study, we assessed the significance and the applicability of the current guidelines for the threshold for abnormal MLE among adult Indigenous Australians. METHODS: Patients who underwent chest CT between 2012 and 2020 among those referred to undergo lung function test (spirometry) were assessed for the presence of MLE which were classified as Group A (no measurable nodes), Group B (<10 mm), Group C (≥10 to 14.99 mm) and Group D (≥15 mm). RESULTS: Of the total 67 patients identified to have MLE, 49 patients had at least two CT scans available for assessment over a median follow-up period of 101.3 weeks (IQR: 62.4, 235.6) and were included in the analysis. Evidence of chronic lung disease was common, with a significant proportion demonstrating either COPD or bronchiectasis and a high proportion with smoking history (93%). During the first CT scan, 34/49 (69%) had >10 mm nodes, of which 12/34 (35%) reduced in size, 22/34 (65%) remained stable, and 3/34 (9%) had malignancy on follow-up. CONCLUSION: Despite most patients demonstrating the presence of significant MLE with varying size and in most >10 mm, the majority remain stable or benign in nature and only a minor proportion showed evidence of lung malignancy. Further prospective studies are needed in the characterisation of MLE among Indigenous patients.

The 'ABC' of respiratory disorders among adult Indigenous people: asthma, bronchiectasis and COPD among Aboriginal Australians - a systematic review.

BACKGROUND: Aboriginal Australians are reported to have higher presence of chronic respiratory diseases. However, comprehensive evidence surrounding this is sparse. Hence, a systematic review was undertaken to appraise the current state of knowledge on respiratory health in the adult Aboriginal Australians, in particular among the three most common respiratory disorders: asthma, bronchiectasis and chronic obstructive pulmonary disease (COPD). METHODS: A systematic review of primary literature published between January 2012 and October 2022, using the databases PubMed and Scopus, was conducted. Studies were included if they reported adult Aboriginal Australian prevalence's or outcomes related to asthma, bronchiectasis or COPD, and excluded if adult data were not reported separately, if Aboriginal Australian data were not reported separately or if respiratory disorders were combined into a single group. Risk of bias was assessed by both Joanne Briggs Institute checklists and Hoys' bias assessment. Summary data pertaining to prevalence, lung function, symptoms, sputum cultures and mortality for each of asthma, bronchiectasis and COPD were extracted from the included studies. RESULTS: Thirty-seven studies were included, involving approximately 33 364 participants (71% female). Eighteen studies reported on asthma, 21 on bronchiectasis and 30 on COPD. The majority of studies (94%) involved patients from hospitals or respiratory clinics and were retrospective in nature. Across studies, the estimated prevalence of asthma was 15.4%, bronchiectasis was 9.4% and COPD was 13.7%, although there was significant geographical variation. Only a minority of studies reported on clinical manifestations (n=7) or symptoms (n=4), and studies reporting on lung function parameters (n=17) showed significant impairment, in particular among those with concurrent bronchiectasis and COPD. Airway exacerbation frequency and hospital admission rates including mortality are high. DISCUSSION: Although risk of bias globally was assessed as low, and study quality as high, there was limited diversity of studies with most reporting on referred populations, and the majority originating from two centres in the Northern Territory. The states with the greatest Aboriginal Australian population (Victoria and New South Wales) reported the lowest number of studies and patients. This limits the generalisability of results to the wider Aboriginal Australian population due to significant environmental, cultural and socioeconomic variation across the population. Regardless, Aboriginal Australians appear to display a high prevalence, alongside quite advanced and complex chronic respiratory diseases. There is however significant heterogeneity of prevalence, risk factors and outcomes geographically and by patient population. Further collaborative efforts are required to address specific diagnostic and management pathways in order to close the health gap secondary to respiratory disorders in this population.

The Impact of Lung Function Parameters on Sleep Among Aboriginal Australians - A Polysomnography and Spirometry Relationship Study.

Background: Sleep disorders such as obstructive sleep apnoea (OSA) are known to overlap significantly with airway diseases in various populations. This study assessed the relationship between lung function parameters against polysomnography (PSG) and continuous positive airway pressure (CPAP) adherence data amongst an Aboriginal Australian population. Methods: Patients who undertook both a diagnostic PSG and spirometry were included. Restrictive, obstructive, and mixed impairments were assessed via global lung function initiative (GLI-2012, ATS/ERS) criteria/guidelines. PSG and CPAP data were evaluated between patients with or without spirometry impairments. Results: Of the total 771 patients, 248 had PSG and spirometry data available (52% female, 44% remote residents, 78% obese). The majority (89%) had OSA (51% severe), 95 (38%) were observed to have a restrictive impairment, and 31 (13%) had an obstructive or mixed impairment on spirometry. Compared to patients with no spirometric impairment, those with restrictive or obstructive/mixed impairments demonstrated significantly lower sleep efficiency (median 84% vs 79% and 78%), higher apnoea-hypopnea index (AHI) during rapid eye movement (REM) sleep (median 32 vs 52 and 55 events/hour), reduced REM oxygen saturation (SpO2) (median 94.0% vs 92.0% and 92.5%) and reduced adherence to CPAP therapy (median 39% vs 22% and 17%). Differences in sleep efficiency, REM AHI, and NREM SpO2 held for patients with obstructive/mixed impairments in multivariate modelling. Conclusion: Aboriginal Australian patients with OSA have a higher concurrent lung function' impairment. Spirometric impairment appears to negatively influence sleep efficiency, nocturnal SpO2 and CPAP adherence. This may have substantial implications for OSA management among Aboriginal Australians.

Oxygen resaturation rate is significantly associated with objectively assessed excessive daytime sleepiness in suspected obstructive sleep apnoea patients.

INTRODUCTION: Commonly utilised metrics such as the apnoea-hypopnoea index show limited correlation to excessive daytime sleepiness (EDS). Oxygen desaturation parameters show better predictive power, however oxygen resaturation parameters have not yet been investigated. Oxygen resaturation may represent increased cardiovascular fitness and thus we hypothesized that a higher resaturation rate would be protective against EDS. METHODS: Oxygen saturation parameters were computed via ABOSA software for adult patients referred for polysomnography and multiple sleep latency test in Israel Loewenstein hospital 2001-2011. EDS was defined as a mean sleep latency (MSL) below 8 min. RESULTS: 1629 patients (75% male, 53% obese, median age of 54 years) were included for analysis. The average desaturation event nadir was 90.4% and resaturation rate 0.59%/second. Median MSL was 9.6 min, and 606 patients met criteria for EDS. Patients who were younger, female, and with larger desaturations had significantly higher resaturation rates (p < 0.001). In multivariate models, adjusted for age, sex, body mass index, and average desaturation depth, resaturation rate showed a significant negative correlation with MSL (z-score standardised beta, -1 (95%CI -0.49, -1.52)), and significantly increased odds ratio (OR) of EDS (OR, 1.28 (95%CI 1.07, 1.53)). The beta associated with resaturation rate was larger, though non-significantly, than that of desaturation depth (difference 0.36 (95% CI -1.34, 0.62), p = 0.470). CONCLUSION: Oxygen resaturation parameters show significant associations with objectively assessed EDS independent of desaturation parameters. Thus, resaturation and desaturation parameters may reflect differing underlying mechanistic pathways and both be considered novel and appropriate markers for assessing sleep-disordered breathing and associated outcomes.

Obstructive sleep apnea in aboriginal Australians: polysomnographic outcomes and symptom perception post-continuous positive airway pressure implementation.

Study Objectives: Obstructive sleep apnea (OSA) is reported to be highly prevalent among Aboriginal Australians. However, no studies have assessed the implementation and efficacy of continuous positive airway pressure (CPAP) therapy in this population. Hence, we compared the clinical, self-reported perception of sleep quality and polysomnographic (PSG) characteristics among Aboriginal patients with OSA. Methods: Adult Aboriginal Australians who underwent both diagnostic (Type 1 and 2) and in-lab CPAP implementation studies were included. Results: Total of 149 patients were identified (46% female, median age 49 years, body mass index 35 kg/m2). The OSA severity was 6% mild, 26% moderate, and 68% severe on the diagnostic PSG. On application of CPAP, there were significant improvements in; total arousal index (diagnostic 29 to 17/h on CPAP), total apnea-hypopnea index (AHI) (diagnostic 48 to 9/h on CPAP), non-rapid eye movement AHI (diagnostic 47 to 8/h on CPAP), rapid eye movement (REM) AHI (diagnostic 56 to 8/h on CPAP) and oxygen saturation (SpO2) nadir (diagnostic 77% to 85% on CPAP) (p < 0.001 for each). Following a single night of CPAP, 54% of patients reported sleeping "better than normal" compared to 12% following the diagnostic study (p = 0.003). In multivariate regression models, males had a significantly lesser change in REM AHI than females (5.7 events/hour less change (IQR 0.4, 11.1), p = 0.029). Conclusions: There is substantial improvement in several sleep-related domains on the application of CPAP among Aboriginal patients with a good initial acceptance of treatment. Whether the positive impact observed in this study translates to better sleep health outcomes with long-term adherence to CPAP therapy is yet to be assessed.

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 ß-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.

Correlation of spirometry indices to chest radiology in the diagnosis of chronic airway disease among regional and rural Indigenous Australians.

BACKGROUND: The majority of Indigenous Australians reside in non-urban locations, with reduced access to chest radiology such as computed tomography (CT). Spirometry and chest X-ray (CXR) may be used in the absence of CT; however, the correlation of spirometry indices to CT-defined chronic airway diseases (i.e. chronic obstructive pulmonary disease (COPD) and bronchiectasis) compared with CXR among Indigenous people is sparsely reported. AIM: To evaluate spirometry indices against CXR and CT findings among adult Indigenous Australians. METHODS: Indigenous patients who had undergone a spirometry test between 2012 and 2020 and had a CXR or chest CT scan assessed for the presence (+ )/absence (- ) of airway diseases were included in this study. RESULTS: Of 643 patients (57% female, 31% remote/very remote), 364 (57%) had CT and CXR available. Patients who were 'CT- and CXR- ' for airway diseases (48%) recorded a mean FVC, FEV1 and FEV1 /FVC of 61%, 59% and 0.76 compared to 57%, 49% and 0.66 in the 'CT+ and CXR- ' group and 53%, 39% and 0.58 in the 'CT+ and CXR+ ' group. CXR showed sensitivity (44%) and specificity (88%), while spirometry showed 62% and 77% compared to CT. Spirometry demonstrated predominately restrictive impairment among 'CT- and CXR- ' and mixed/obstructive impairment among 'CT+ and CXR- ' and 'CT+ and CXR+ ' groups. CONCLUSION: Indigenous Australians tend to demonstrate restrictive impairment in the absence of radiological evidence of airway disease. However, in the presence of airway disease, combinations of mixed and obstructive impairments were common. Obstructive impairment shows greater sensitivity for identifying COPD than that shown by CXR; however, CXR shows greater specificity. Hence, spirometry in conjunction with chest radiology should be utilised to aid in the assessment of airway diseases in this population.

Validity of the new 'Top End Sleepiness Scale' 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 apnoea (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' was used among Indigenous Australians against STOP-Bang screening tool for 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 Apnoea-Hypopnoea Index (AHI, ≥15) against the 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. Area under the curve 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 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%), although specificity was comparable (83% vs 91% respectively). CONCLUSIONS: The TESS screening tool could be a useful standalone or could be adopted alongside the STOP-Bang OSA screening tools in the clinical assessment of sleep disorders among Indigenous Australians.

Flexible bronchoscopy indications and outcomes between indigenous and non-indigenous patients in the Northern Territory of Australia.

BACKGROUND: There is sparse evidence in the literature in relation to indications and outcomes among adult indigenous patients requiring a flexible bronchoscopy (FB). In this study, FB indications and outcomes between indigenous and non-indigenous patients were assessed. AIM: To assess the similarities and differences of FB indications and outcomes between indigenous and non-indigenous patients. METHODS: Self-reported indigenous status, resident locality and the primary indication for FB were assessed. The FB procedures details, results of microbiology, cytology and histopathology were compared between indigenous and non-indigenous patients. Chest computed tomography (CT) was also analysed for its relationship to FB outcomes. RESULTS: Of the 403 patients, 111 (28%) were indigenous, and indigenous patients were younger (mean difference 11 years) and had a higher proportion of remote residence (70% vs 13%). Malignancy (40%) and infection (31%) were the most common indications for FB, although indigenous patients reported significantly more haemoptysis (15% vs 9%). No differences were noted in findings of the preceding chest CT scans. For positive microbiology, indigenous patients had a higher presence of Streptococcus pneumoniae (30% vs 9%), while non-indigenous patients had a higher presence of Pseudomonas aeruginosa (43% vs 11%) and mycobacteria (15% vs 4%). There was no significant difference between indigenous and non-indigenous patients for a positive histopathology, particularly for a diagnosis of lung malignancy (58% vs 54%). CONCLUSIONS: This study has demonstrated that adult indigenous patients requiring a FB are significantly younger, tend to reside in remote communities and demonstrate differing microbiology with no significant difference in the diagnostic outcomes for lung malignancy. Ethnic status or remoteness should not preclude indigenous patients to undergo a FB if clinically indicated.

The Prevalence of Bronchodilator Responsiveness "Asthma" Among Adult Indigenous Australians Referred for Lung Function Testing in the Top End Northern Territory of Australia.

Background: Among Indigenous Australians, studies examining the clinical significance of airway bronchodilator responsiveness (BDR) are limited. In this retrospective study, we examined the nature of underlying lung disease in adult Indigenous patients with BDR referred for lung function testing (LFT) in the Top End Health Service region of the Northern Territory of Australia. Methods: Presence or absence of BDR as per usual (FVC or FEV1 change pre to post ≥12% and ≥0.2L) and updated (2021 ">10% predicted) ATS/ERS criteria among Indigenous and non-Indigenous Australians was determined. The radiological findings in the Indigenous study participants with and without BDR were next assessed for the presence of underlying chronic airway/lung disease. Results: We found that 123/742 (17%) Indigenous and 578/4579 (13%) non-Indigenous patients had a significant BDR. Indigenous patients with BDR were younger (mean difference 7 years), with a greater proportion of females (52 vs 32%), underweight (15 vs 4%) and current smokers (52 vs 25%). Indigenous patients with BDR displayed lower LFT values, and a higher proportion exhibited FVC BDR compared to non-Indigenous (34 vs 20%). Almost half (46%) of Indigenous patients with BDR had evidence of COPD and/or bronchiectasis on radiology. Adjusting for the presence of radiologic or spirometric evidence of COPD, the presence of BDR was similar between Indigenous and non-Indigenous patients (5-8 vs 7-11%), irrespective of which BDR criteria was used. Conclusion: BDR was higher overall among Indigenous in comparison to non-Indigenous patients; however, a significant proportion of Indigenous patients demonstrating BDR had evidence of underlying COPD/bronchiectasis. This study highlights that although presence of BDR among Indigenous people may indicate asthma, it may also be observed among patients with COPD/bronchiectasis or could represent asthma/COPD/bronchiectasis overlap. Hence, a combination of clinical history, LFT and radiology should be considered for precise diagnosis of lung disease in this population.

Comparison of polysomnographic characteristics between low birthweight and normal birthweight children in the Northern Territory of Australia: A case-control study.

OBJECTIVES: To describe the sleep architecture of pediatric patients according to whether they were born low birthweight (birthweight <2500 g, LBW) or normal birthweight (birthweight >2500 g). DESIGN: Case control study. SETTING: Pediatric sleep laboratory in the Northern Territory of Australia during a 5-year study period (2015- 2020). PARTICIPANTS: Pediatric patients (aged <18 years) referred to the specialist sleep service for assessment of clinically suspected sleep disorders. MEASUREMENTS: Sleep onset latency, rapid eye movement (REM) sleep latency, wake time after sleep onset, total sleep time, sleep efficiency, non-rapid eye movement stages N1/N2/N3, and REM sleep duration, total/spontaneous/respiratory/limb related arousal indexes, total/non-rapid eye movement/REM obstructive apnea-hypopnea index and oxygen saturation. RESULTS: One hundred and seventy-two pediatric patients had birthweight data available of whom 19 were LBW. LBW patients showed significantly greater sleep disruption and higher prevalence of poor sleepers (<80% efficiency). In multivariate regression models, increasing birthweight was associated with significantly greater sleep efficiency and total sleep time. After accounting for gestational age LBW was associated with increased odds of obstructive sleep apnea. CONCLUSIONS: Among pediatric patients LBW is associated with increased sleep disruption and reduced sleep efficiency. This is attenuated by gestational age, though both gestational age and LBW significantly influence odds of obstructive sleep apnea. This sleep health deficit may contribute to development of chronic disease in this vulnerable population, and should be monitored to provide avenues for early intervention.

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 quality and obstructive sleep apnoea in Indigenous and non-Indigenous Australian children.

BACKGROUND: Literature pertaining to the prevalence of obstructive sleep apnoea (OSA) and sleep quality among Indigenous Australian children is sparse. This study assessed various sleep related parameters and outcomes between Indigenous and non-Indigenous Australian children. METHODS: Children referred to the sleep health service in the Northern Territory of Australia for a clinically suspected sleep disorder between 2015 and 2021 were included in this study. Self-reported sleep measures alongside polysomnography data were assessed and compared between these two diverse ethnic population. RESULTS: Of the 671 sleep studies assessed, 121 (18%) were from Indigenous children. The majority of patients were male (61%), with a median age of 5.7 (3.5, 8.9) years, and body mass index (BMI) in the normal range (57%). Indigenous children were significantly older (median 7.2 years (4.5, 11.9), with a higher BMI (p = 0.005) and a greater proportion living in very remote locality (14% vs. 6% non-Indigenous, p = 0.001). Indigenous children had higher Paediatric Daytime Sleepiness Scale scores (p = 0.001), higher screen use before bed (p = 0.005), later bedtimes (p = 0.001) and reduced total sleep time (p = 0.034) compared to non-Indigenous children. Prevalence of OSA was higher in Indigenous children (55% vs. 48%) and with greater severity compared to non-Indigenous children. CONCLUSIONS: In this study, OSA was more prevalent and more severe in Indigenous children than their non-Indigenous peers. However, this may not necessarily be extrapolated to the general Indigenous paediatric population. Sleep hygiene and sleep quantity was also decreased further impacting adequate sleep. This highlights the importance of identifying and managing these addressable parameters and for targeted interventions.