Prevalence and nature of lung function abnormalities among Indigenous Australians referred to specialist respiratory outreach clinics in the Northern Territory

Factors related with lung functions among Orang Asli in Tasik Chini, Malaysia: a cross-sectional study

BACKGROUND

Orang Asli lifestyle and household setting may influence their health status especially respiratory system and lung functions. This cross-sectional study was carried out to investigate the status of lung functions of Orang Asli community and the associated factors.

METHODS

Data collection was carried out from November 2017 until May 2018 among 211 Orang Asli respondents aged 18 years old and above, who lived in five villages in Tasik Chini, Pahang. All respondents who fulfilled the inclusion criteria were recruited in this study. Interview-guided questionnaire was administered, and spirometry test that include Forced Expiratory Volume in one second (FEV1), Forced Vital Capacity (FVC), and Peak Expiratory Flow Rate (PEFR) was carried out. Data were analyzed using SPSS software version 23.0. In the first stage, descriptive analysis was done to describe the characteristics of the respondents. In the second stage, bivariable analysis was carried out to compare proportions. Finally, multiple logistic regression was performed to assess the effects of various independent predictors on spirometry parameters.

RESULTS

The respondents' age ranged from 18 to 71 years old in which 50.2% of them were female. The majority ethnicity in Tasik Chini was Jakun tribe (94.3%). More than half of the respondents (52.1%) were current smoker, 5.2% were ex-smoker and 41.7% were non-smoker. More than half of them (62.1%) used woodstove for cooking, compared to only 37.9% used cleaner fuel like Liquefied Petroleum Gas (LPG) as a fuel for everyday cooking activity. The lung function parameters (FEV1 and FVC) were lower than the predictive value, whereas the ratio of Forced Expiratory Volume in one second and Forced Vital Capacity (FEV1/FVC) (%) and PEFR were within the predictive value. The FEV1 levels were significantly associated with age group (18-39 years old) (p = 0.002) and presence of woodstove in the house (p = 0.004). FVC levels were significantly associated with presence of woodstove in the house (p = 0.004), whereas there were no significant associations between all factors and FEV1/FVC levels.

CONCLUSIONS

FEV1 levels were significantly associated with age group 18-39 years old, whereas FVC levels were significantly associated with the presence of woodstove in the house. Thus, environmental interventions such as replacing the use of woodstove with LPG, need to be carried out to prevent further worsening of respiratory health among Orang Asli who lived far from health facilities. Moreover, closer health monitoring is crucial especially among the younger and productive age group.

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.

Association between perinatal and early life exposures and lung function in Australian Indigenous young adults: The Aboriginal Birth Cohort study

BACKGROUND AND OBJECTIVE

Despite the high burden of respiratory disease amongst Indigenous populations, prevalence data on spirometric deficits and its determinants are limited. We estimated the prevalence of abnormal spirometry in young Indigenous adults and determined its relationship with perinatal and early life factors.

METHODS

We used prospectively collected data from the Australian Aboriginal Birth Cohort, a birth cohort of 686 Indigenous Australian singletons. We calculated the proportion with abnormal spirometry (z-score <-1.64) and FEV1 below the population mean (FEV1 % predicted 0 to -2SD) measured in young adulthood. We evaluated the association between perinatal and early life exposures with spirometry indices using linear regression.

RESULTS

Fifty-nine people (39.9%, 95%CI 31.9, 48.2) had abnormal spirometry; 72 (49.3%, 95%CI 40.9, 57.7) had a FEV1 below the population mean. Pre-school hospitalisations for respiratory infections, younger maternal age, being overweight in early childhood and being born remotely were associated with reduced FEV1 and FVC (absolute, %predicted and z-score). The association between maternal age and FEV1 and FVC were stronger in women, as was hospitalization for respiratory infections before age 5. Being born remotely had a stronger association with reduced FEV1 and FVC in men. Participants born in a remote community were over 6 times more likely to have a FEV1 below the population mean (odds ratio [OR] 6.30, 95%CI 1.93, 20.59).

CONCLUSION

Young Indigenous adults have a high prevalence of impaired lung function associated with several perinatal and early life factors, some of which are modifiable with feasible interventions.

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.

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.

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 '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.

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.

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.

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.

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.

Implications of using the GLI-2012, GOLD and Australian COPD-X recommendations in assessing the severity of airflow limitation on spirometry among an Indigenous population with COPD: an Indigenous Australians perspective study

Background

Assessment of airflow limitation (AFL) is crucial in the clinical evaluation of patients with chronic obstructive pulmonary disease (COPD). However, in the absence of normative reference values among adult Australian Indigenous population, the implications of utilising the Global Lung Function Initiative (GLI-2012), Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the Australian concise COPD-X recommended severity classifications is not known. Moreover, spirometry values (forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV₁)) are observed to be 20%–30% lower in an apparently healthy Indigenous population in comparison to Caucasian counterparts.

Methods

Adult Indigenous patients diagnosed to have COPD on spirometry (postbronchodilator (BD) FEV₁/FVC <0.7 ((GOLD, (COPD-X)) and ≤lower limit of normal (others/mixed reference equations) for GLI-2012) were assessed for AFL severity classifications on Post-BD FEV₁ values (mild, moderate, severe, very severe) as per the recommended classifications.

Results

From a total of 742 unique patient records of Indigenous Australians, 253 were identified to have COPD via GOLD/COPD-X criteria (n=238) or GLI-2012 criteria (n=238) with significant agreeance between criteria (96%, κ=0.901). Of these, the majority were classified as having moderate or severe/very-severe AFL with significant variability across classification criteria (COPD-X (40%–43%), GOLD (33%–65%), GLI-2012 (18%–75%)). The FVC and FEV₁ values also varied significantly between classification criterion (COPD-X/GOLD/GLI-2012) within the same AFL category, with COPD-X ‘moderate’ AFL almost matching ‘severe’ AFL categorisation by GOLD or GLI-2012.

Conclusions

Health professionals caring for Indigenous patients with COPD should be aware of the clinical implications and consequences of utilising various recommended AFL classifications in the absence of validated spirometry reference norms among adult Indigenous patients.

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.

Utility and outcomes among Indigenous and non-Indigenous patients requiring domiciliary oxygen therapy in the regional and rural Australian population

OBJECTIVE

To evaluate the utility and outcomes for Indigenous and non-Indigenous patients requiring domiciliary oxygen therapy.

DESIGN

Retrospective study.

SETTING

Patients residing in the regional and rural Top End Health Service region of the Northern Territory of Australia.

PARTICIPANTS

Indigenous and non-Indigenous patients prescribed domiciliary oxygen therapy between 2018 and 2020.

INTERVENTIONS

Demographics and clinical indication for domiciliary oxygen therapy and mortality were analysed.

MAIN OUTCOME MEASURES

Differences between Indigenous patients requiring domiciliary oxygen therapy in comparison with their non-Indigenous counterparts.

RESULTS

Of the 199 study participants, the majority were male (51%), non-Indigenous (77%) and urban residents (72%). Overall chronic obstructive pulmonary disease was the most common indication for domiciliary oxygen therapy (51%) followed by palliative intent (22%). Indigenous patients were significantly younger (61 vs 73 years), with a higher proportion of males (62% vs 45%, P = .039) and remote residents (62% vs 8%, P < .001). Among Indigenous patients, a significantly greater proportion of domiciliary oxygen therapy was indicated for chronic obstructive pulmonary disease and bronchiectasis (16% vs 1%, P < .001). Among non-Indigenous patients, malignancies were a more common indication for domiciliary oxygen therapy. A similar proportion of Indigenous and non-Indigenous patients were prescribed domiciliary oxygen therapy for palliative intent (31% and 20%, P = .108); however, the underlying diagnosis differed significantly, with a greater proportion of chronic obstructive pulmonary disease among Indigenous patients (43% vs 13%, P = .030) and malignancy among the non-Indigenous patients (73% vs 43%, P = .050). Mortality and length of survival were not significantly different by Indigenous status. Linear regression showed longer survival with domiciliary oxygen therapy for chronic obstructive pulmonary disease.

CONCLUSION

Indigenous Australian patients living in remote communities will likely derive the same benefits and outcomes of domiciliary oxygen therapy as non-Indigenous peers.

Determinants and Follow-up of Lung Function Data from a Predominantly First Nations Cohort of Adults Referred to Specialist Respiratory Outreach Clinics in Regional and Remote Queensland

PURPOSE

Northern Territory (NT)-based clinical service data suggest substantial lung function impairment amongst First Nations adults as young as 18-40 years. Our objectives were to describe the burden of disease and lung function of adults living in regional-remote Queensland, identify determinants of lung function, and evaluate the impact of a specialist respiratory outreach service on lung function.

METHODS

Retrospective 8-year cohort study (February 2012-March 2020) of 1113 First Nations Australian adults (and 648 non-First Nations adults) referred to respiratory outreach clinics in regional-remote Queensland.

RESULTS

In the combined cohort, the forced expiratory volume in 1 s (FEV₁) was clinically abnormal for 54% of First Nations patients (51% of non-First Nations patients), forced vital capacity (FVC) for 46% (36%), FEV₁/FVC% for 30% (36%), and gas diffusing capacity (D_LCO) for 44% (37%). A respiratory diagnosis was assigned by a respiratory physician in 78% of First Nations (76% non-First Nations) patients. Smoking, household smoke exposure, underweight BMI, and respiratory disease were associated with reduced lung function. In the 40% of patients (709/1765) followed up, FEV₁ and FVC significantly improved (mean change: zFEV₁ = 0.15 [95% CI 0.10-0.20]; zFVC = 0.25 [0.20, 0.31]), and FEV₁/FVC% significantly reduced (mean =  - 0.10 [95%CI - 0.07 to - 0.03]), with no significant change in D_LCO. Patients with COPD had lower FEV₁ improvement, whilst underweight and obese patients had lower FVC improvement.

CONCLUSION

Regional-remote First Nations adult Queenslanders have higher lung function than previously reported, with no lung function decline observed at follow-up visit, including for those with respiratory disease.

Critical analysis of spirometric patterns in correlation to chest computed tomography among adult Indigenous Australians with chronic airway diseases

Background: There is sparse literature evidence in the spirometric patterns of adult Indigenous Australians with and without chest computed tomography (CT)-proven chronic airway diseases (CADs).Methods: Participants spirometry testing graded as acceptable for quality and had a chest CT scan showing radiographic evidence of CADs were included for analysis.Results: Of the 1350 spirometric tests performed between 2012 and 2020, a total of 212 patients with a mean age of 53 years and 54% females were eligible to be included. One-third (30%) had normal chest CT (without CADs), 35% had predominant COPD, 19% bronchiectasis and 16% combined COPD and bronchiectasis. Percentage predicted values for forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁) both pre- and post- bronchodilator were significantly reduced for all participants - FVC: CT-normal 64%, 65%; COPD 58%, 62%; bronchiectasis 54%, 54%; combined COPD and bronchiectasis 50%, 53%. FEV₁: CT-normal 62%, 65%; COPD 46%, 49%; bronchiectasis 48%,51%; combined COPD and bronchiectasis 36%,40%. FEV₁/FVC was only reduced for CT abnormality patients - CT-normal 96%,98%; COPD 77%,77%; bronchiectasis 87%,89%; combined COPD and bronchiectasis 71%,72%.Conclusions: Restrictive spirometric pattern is common and an obstructive pattern with COPD, in isolation or when COPD coexists with bronchiectasis.

2004 chronic obstructive pulmonary disease with and without bronchiectasis in Aboriginal Australians: a comparative study

BACKGROUND

Chronic respiratory disorders are highly prevalent in Aboriginal Australian population, including chronic obstructive pulmonary disease (COPD) and bronchiectasis. However, there is paucity of information in the literature among Aboriginal patients with underlying COPD with and without bronchiectasis.

AIMS

In this retrospective study we evaluated the demographic and clinical characteristics of adult Aboriginal Australian patients with a clinical diagnosis of COPD with and without bronchiectasis from the remote communities of the Northern Territory of Australia.

METHODS

Clinical records were reviewed to extract information on demographics, respiratory and medical comorbid conditions, COPD directed treatment, hospital admission frequency and exacerbations. Chest radiology were reviewed to evaluate the presence or absence of bronchiectasis. Spirometry results, sputum culture and cardiac investigations were also recorded.

RESULTS

Of the 767 patients assessed in the remote community respiratory outreach clinics 380 (49%) patients had a clinical diagnosis of COPD. Chest X-ray and computed tomography scan were available to evaluate the presence of bronchiectasis in 258 patients. Of the 258/380 patients, 176/258 (68.2%) were diagnosed to have COPD alone and 82/258 (31.8%) had bronchiectasis along with COPD. The mean age was 56 and 59 years among patients with and without bronchiectasis, respectively, and 57% were males with bronchiectasis. Patients with bronchiectasis had lower body mass index (22 vs 24 kg/m² ), frequent hospital admissions (2.0 vs 1.5/year) and productive cough (32.1% vs 28.9%). Spirometry showed 77% had forced expiratory volume in 1 s (FEV₁ )/forced vital capacity ratio <0.7. In 81% and 75% of patients with and without bronchiectasis the FEV₁ /forced vital capacity ratio was <0.7 and the mean FEV₁ was 39% and 43% respectively.

CONCLUSIONS

About 32% of Aboriginal Australians had co-existent bronchiectasis with COPD. Lower body mass index, productive cough, frequent hospital admission and marginally more severe reduction in lung function were noted among patients with COPD and bronchiectasis compared to those with COPD in isolation.

Comparison of clinical manifestation among Australian Indigenous and non- Indigenous patients presenting with pleural effusion

BACKGROUND

There is sparse evidence in the literature in relation to the nature and causes of pleural effusion among Australian Indigenous population.

METHODS

In this retrospective study, Indigenous and non-Indigenous adults diagnosed to have pleural effusion over a two-year study period were included for comparative analysis.

RESULTS

Of the 314 patients, 205 (65%) were non-Indigenous and 52% were males. In comparison to non-Indigenous, the Indigenous patients were younger (50 years (IQR 39,60) vs 63 years (IQR 52,72), p<0.001), females (61% vs 41%, p=0.001), have higher prevalence of renal and cardiovascular disease and tend to have exudative effusion (93% vs 76%, p=0.032). Infections was judged to be the most common cause for effusion in both groups, more so among the Indigenous cohort. Effusion secondary to renal disease was higher (13% vs 1%, p<0.001) among Indigenous Australians, in contrast malignant effusions were higher (13% vs 4%, p=0.004) among non-Indigenous. Length of hospital stay was longer for Indigenous patients (p=0.001), and a greater proportion received renal dialysis (13% vs 1%, p<0.001). Intensive care unit (ICU) admissions rates were higher with infective etiology of pleural effusion (82% vs. 53% Indigenous & 44% vs. 39% non-Indigenous respectively). Re-presentations to hospital were higher among Indigenous patients (46% vs 33%, p=0.046) and were associated with renal and cardiac disease and malignancy in non-Indigenous.

CONCLUSION

There are significant differences in the way pleural effusion manifests among Australian Indigenous patients. Understanding these differences may facilitate approaches to the management and to implement strategies to reduce morbidity and mortality in this population. This article is protected by copyright. All rights reserved.

Comparison of diffusing capacity of carbon monoxide (DLCO) and total lung capacity (TLC) between Indigenous Australians and Australian Caucasian adults

Background and objective

Currently there is paucity of evidence in the literature in relation to normative values for diffusing capacity of carbon monoxide (DLCO) and total lung capacity (TLC) among Indigenous Australians. Hence, in this study we assessed the DLCO and TLC parameters among Indigenous Australians in comparison to Australian Caucasian counterparts.

Methods

DLCO and TLC values were assessed and compared between Indigenous Australians and Australian Caucasians matched for age, sex and body mass index, with normal chest radiology.

Results

Of the 1350 and 5634 pulmonary function tests assessed in Indigenous Australian and Australian Caucasian adults respectively, a total of 129 Indigenous Australians and 197 Australian Caucasians met the inclusion criteria. Absolute DLCO and TLC values for Indigenous Australians were a mean 4.3 ml/min/mmHg (95% CI 2.86, 5.74) and 1.03 L (95% CI 0.78, 1.27) lower than Australian Caucasians (p<0.01). Percentage predicted values were 15.38 (95% CI 11.59, 19.17) and 16.63 (95% CI 13.59, 19.68) points lower for DLCO and TLC, respectively. Lower limit of normal (LLN) values did not significantly differ between groups, however a significantly greater proportion of Indigenous Australians recorded values below the LLN in comparison to Australian Caucasians for DLCO (64 vs. 25%, p<0.01) and TLC (66 vs. 21%, p<0.01). Significant differences for the interaction of sex on DLCO and TLC were noted in Australian Caucasians, with reduced or absent sex differentiation among Indigenous Australians.

Conclusions

There are significant differences in DLCO and TLC parameters between Indigenous Australian compared to Australian Caucasians. Appropriate DLCO and TLC norms need to be established for Indigenous Australians.

Obstructive Sleep Apnoea and Cardiac Disease Among Aboriginal Patients in the Northern Territory of Australia

BACKGROUND

There is paucity of information on obstructive sleep apnoea (OSA) and cardiac diseases among Aboriginal Australian patients. This study evaluates the association of various cardiac disease profiles among Aboriginal patients undergoing a diagnostic polysomnography (PSG).

METHOD

In this 5-year retrospective study demographics, clinical characteristics, medical and cardiac -conditions were analysed.

RESULTS

There were total of 340 eligible patients included in the study. The median age was 47 (38-57) years, 51% were males and obesity was noted in 78%. In the overall study participants, cardiac diseases were present in 46%: coronary artery disease (CAD) in 27%, pulmonary hypertension (PH) 19% and atrial fibrillation (AF) 14%. Diabetes and hypertension were noted in 42 and 41% of patients. Overall, 73/340 (21.5%) had two, 69/340 (20.3%) three, 55/340 (16.2%) four, 40/340 (11.8%) five and 10/340 (2.9%) had six comorbidities. In the overall study participants, 297/340 (87%) had OSA (Apnoea-Hypopnoea Index [AHI]>5/hour). Co-occurrence of OSA and cardiac diseases was found in 140/297 (47%), CAD being the commonest (27%). Patients with OSA had a higher number of comorbidities compared to patients without sleep apnoea. Hospital admissions frequency showed a median 2 (IQR: 0-4) times readmission rates since the diagnosis of OSA overall compliance with CPAP therapy was observed in 63 (43%).

CONCLUSION

Our study demonstrated that a significant proportion of Aboriginal patients with OSA have co-existing cardiac diseases, with CAD being the commonest. Patients with OSA had a higher number of comorbidities compared to patients without sleep apnoea. Furthermore, hospital admission frequency increased among OSA patients with multiple comorbidities.

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.

Lung function parameters among Australian Aboriginal 'apparently healthy' adults: an Australian Caucasian and Global Lung Function Initiative (GLI-2012) various ethnic norms comparative study

Background: There is sparse literature evidence evaluating the applicability of the GLI-2012 spirometric norms for Australian Aboriginal adults.Methods: Lung function parameters (LFPs) were compared between Australian Aboriginal and Australian Caucasians, and the fit of Australian Aboriginals LFPs with various ethnic GLI equations was tested.Results: Of 1350 and 5634 Pulmonary function tests (PFTs) in Australian Aboriginal and Australian Caucasian adults, 153 and 208 PFTs matched for anthropometrics and normal chest radiology, respectively. Absolute FVC and FEV₁ values were 20% lower in Australian Aboriginals compared to Australian Caucasians. Differences remained significant after accounting for age, sex, height, weight and smoking status in multivariate regression (FVC -0.84 L (-0.98, -0.71), FEV₁ - 0.72 L (-0.84, -0.59), but with nearly preserved FEV₁/FVC. GLI-2012 transformation resulted in z-scores significantly below zero for each of FVC, FEV₁ and FEV₁/FVC with z-scores ranging from -4.52 (-4.87, -4.16) for North East Asian FVC transformation for males, to -0.34 (-0.73, 0.05) for Black FVC transformation for females.Conclusions: Australian Aboriginal adults had 20% lower values for FVC and FEV₁ but nearly preserved absolute FEV₁/FVC in comparison to Australian Caucasians. The GLI-2012 spirometric norms do not appear to fit for Australian Aboriginal adults regardless of which ethnicity options selected, including 'others/mixed'.

Expression of Matrix Metalloproteinase-2, Matrix Metalloproteinase-9, Tissue Inhibitor of Metalloproteinase-1, and Changes in Alveolar Septa in Patients with Chronic Obstructive Pulmonary Disease

Background

This study investigated the relationship between the pathological alteration of alveolar septa and (1) pulmonary function and (2) matrix metalloproteinase (MMP)-2, MMP-9, and tissue inhibitor matrix metalloproteinase 1 (TIMP-1) expression in chronic obstructive pulmonary disease (COPD).

Material/Methods

Sixty patients with pulmonary disease were divided into control (n=20) and COPD (n=40) groups. Postoperative lung tissue specimens were examined. Hematoxylin and eosin and elastin van Gieson staining detected pathological alterations of pulmonary alveolar septa. Septa thickness was measured. MMP-2, MMP-9, and TIMP-1 expression levels were detected by immunohistochemical staining. Correlations were determined by Pearson analysis.

Results

Forced expiratory volume in 1 s (FEV₁), forced vital capacity, FEV₁ percent predicted (FEV₁%pre), and diffusion capacity of carbon monoxide percent predicted (DLCO%pre) in COPD patients were significantly lower than in those of the control group (P<0.05). MMP-2, MMP-9, and TIMP-1 expression levels were significantly higher in the COPD group than in control, especially the severe group (P<0.05). Septa thickness was negatively correlated with FEV₁%pre (r=−0.335; P<0.05) and positively correlated with MMP-2 and TIMP-1 expression (P<0.05). Proportion of collagenous fiber was negatively correlated with FEV₁%pre and DLCO%pre (P<0.01), and positively correlated with MMP-2, MMP-9, and TIMP-1 expression (P<0.01). Proportion of elastic fibers was negatively correlated with collagenous fiber.

Conclusions

The pathological alteration of alveolar septa was correlated with pulmonary function and expression levels of MMP-2, MMP-9, and TIMP-1, which can play vital roles in COPD progression.

Culturally Appropriate Outreach Specialist Respiratory Medical Care Improves the Lung Function of Children in Regional and Remote Queensland

BACKGROUND AND OBJECTIVES

Indigenous Respiratory Outreach Care (IROC) is a culturally appropriate specialist respiratory service established to deliver multidisciplinary respiratory care to regional and remote Queensland communities. Our objective was to evaluate the impact of an outreach specialist respiratory service on the spirometry of children attending IROC clinics, particularly Indigenous children with asthma and bronchiectasis.

METHODS

Retrospective single-arm cohort study of 189 children who performed spirometry at twelve sites across regional and remote Queensland between October 2010 and December 2017. Each child's baseline spirometry was compared to their best spirometry at follow-up visit occurring within (1) 12 months of their most recent visit with at least 12 months of specialist care and; (2) each year of their first 3 years of care.

RESULTS

Forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) z-scores improved significantly across the whole group from baseline to follow-up (change in z-scores (Δz) of FEV₁ = 0.38, 95% CI 0.22, 0.53; ΔzFVC = 0.36, 95% CI 0.21, 0.51). In subgroup analyses, lung function significantly improved in Indigenous children (n = 141, ΔzFEV₁ = 0.37, 95% CI 0.17, 0.57; ΔzFVC = 0.36, 95% CI 0.17, 0.55) including those with asthma (n = 117, ΔzFEV₁ = 0.41, 95% CI 0.19, 0.64; ΔzFVC = 0.46, 95% CI 0.24, 0.68) and bronchiectasis (n = 38, ΔzFEV₁ = 0.33, 95% CI 0.07, 0.59; ΔzFVC = 0.26, 95% CI - 0.03, 0.53). Significant improvements in FEV₁ and FVC were observed within the first and second year of follow-up for Indigenous children, but not for non-Indigenous children.

CONCLUSION

The IROC model of care in regional and remote settings leads to significant lung function improvement in Indigenous children with asthma and bronchiectasis.

Gender Differences in the Clinical and Polysomnographic Characteristics Among Australian Aboriginal Patients with Obstructive Sleep Apnea

BACKGROUND

In this study, we assessed the clinical and polysomnographic (PSG) characteristics according to gender among Australian Aboriginal men and woman diagnosed to have obstructive sleep apnea (OSA).

METHODS

In this retrospective study, all adult Aboriginal patients over 18 years of age diagnosed to have OSA with an apnea hypopnea index (AHI) > 5/hour over a 5 year period were included.

RESULTS

Of the 337 patients (168 females and 169 males), who underwent a diagnostic PSG, 297 (88%) were diagnosed to have OSA (AHI) >5/hour), 154/297 males (52%) and 143/297 females (48%). Amongst male and female patients with OSA, 63% and 37% were in the severe spectrum (AHI>30/hour). The male cohort had higher stage N1 NREM sleep (P<0.001), reduced N3 NREM sleep (P<0.001), higher AHI severity (P<0.001), higher NREM AHI (P<0.001), and high arousal index (P<0.005). REM sleep-related AHI was higher among female patients with all severity of OSA, along with severe oxygen desaturation during REM sleep. Among patients with severe OSA, the female cohort were younger (age 46 years vs 49 years, P=0.030) and had higher BMI with all severity of OSA, while males had larger neck circumference compared to females. Hypertension increased the odds of severe OSA versus the combined odds of mild and moderate OSA for both genders.

CONCLUSION

This study highlights some important differences in the way sleep apnea manifests in Australian Aboriginal males and females and further studies are warranted to explore avenues to look for a physiological basis for these observations and targeted interventions.

Sleep apnoea among Australian Aboriginal and non-Aboriginal patients in the Northern Territory of Australia—a comparative study

Australian Aboriginal and Torres Straight Islanders (ATSI) are noted to have a higher burden of chronic health conditions. However, there is a paucity of data on obstructive sleep apnoea (OSA) in this population. In this retrospective study, we evaluated the clinical and polysomnographic (PSG) characteristics of ATSI and non-ATSI adult patients who underwent diagnostic PSG between 2011 and 2015. There were a total of 3078 patients. Of the total, 403 (13%) were of ATSI origin. Among those of ATSI origin, 61% were male and 39% females, while among the non-ATSI cohort, 66% were males. The median age was 47.8 years in ATSI and 51.5 years in the non-ATSI cohort. In the combined cohort, body mass index was more than 30 kg/m2 (61%), hypertension (14.4%), diabetes (17.8%), and heart disease (23.3%). The ATSI patients had higher rates of class III obesity (27 vs. 15%), hypertension (26 vs. 14%), cardiac disease (34 vs. 23%), and diabetes (37 vs. 17%). Among all the study participants, the PSG confirmed 83.7% of the patients had an apnoea–hypopnea index (AHI) more than 5/h, mild (AHI 5–15/h) in 28.4%, moderate (AHI 15–30/h) in 22.3%, and severe (AHI &gt; 30/h) in 33.0%. Among the ATSI patients, 46% had severe OSA. The median total AHI value was higher in the ATSI population (25, interquartile range [IQR]: 11–58) compared to the non-ATSI (17, IQR: 7–36), and in rural/remote population (19, IQR: 8–42) compared to urban (17, IQR: 7–37). This trend was similar for NREM (non-rapid eye movement)-AHI and REM (rapid eye movement)-AHI scores, although statistically significant difference was found only with ATSI status. In the combined cohort the probability of (OR = 1.62, 95% CI: 1.32–2.00, p &lt; 0.001) of severe OSA was 62% higher in individual with hypertension, however, when stratified by ATSI status, the association was only significant in the non-ATSI population (OR = 1.53 95% CI: 1.21–1.94, p &lt; 0.001). The odds of severe AHI was also significantly associated with heart disease (1.37; 95% CI: 1.14,1.63, p &lt; 0.001), diabetes (1.74; 95% CI: 1.43,2.10; p &lt; 0.001) and smoking (1.28; 95% CI: 1.09,1.50, p = 0.0023) in the overall study cohort. In both ATSI and non-ATSI patients, body mass index, neck circumference, sleep efficiency, wake after sleep onset, and respiratory arousal index were significantly higher and independently associated with severe AHI.

Chronic Obstructive Pulmonary Disease In Aboriginal Patients Of The Northern Territory Of Australia: A Landscape Perspective

Background

The Aboriginal population of Australia has a higher burden of chronic health conditions than non-Aboriginal Australians. However, there is a paucity of data on clinical and demographic characteristics of chronic obstructive pulmonary disease (COPD) in this population.

Method

In this retrospective study we evaluated the clinical, demographic and environmental influences in adult Aboriginal patients with COPD living in the regional and remote communities of the Northern Territory of Australia.

Results

There were 380 patients (49%) with a diagnosis of COPD of the 767 patients referred to specialist respiratory outreach clinics. The mean age was 57 years (56% were female) and mean±SD BMI was 24.30±7.01 kg/m². Smoking history was noted in 93% of the study cohort. The most common respiratory symptom was shortness of breath in 62%, and inhaled medications (salbutamol, tiotropium, salmeterol/fluticasone) were used by 79%, 44% and 58% of patients, respectively. Spirometry showed obstructive impairment (FEV₁/FVC <0.7) in 79% (0.56±0.17), with mean FEV₁ 42% of predicted, and a bronchodilator response was present in 28.6%. Comorbid bronchiectasis was diagnosed in 49.8% along with COPD. The relationship between COPD and community demography showed a higher proportion of smokers and those with underlying bronchiectasis to have lower FEV₁/FVC ratios. Communities with a higher proportion of asthma were younger and had higher smoking rates. Mortality increased with increasing number of exacerbations and hospital admissions.

Conclusion

The Aboriginal population with COPD has a higher prevalence of smoking, moderate to severe airflow obstruction on spirometry and frequently co-diagnosed bronchiectasis with increased severity of ventilatory impairment.