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

Applicability and Validity of the "Bronchiectasis Severity Index" (BSI) and "FACED" Score in Adult Aboriginal Australians

Background

The prevalence of bronchiectasis is significantly higher among adult Aboriginal Australians (the Indigenous peoples of Australia) compared to non-Aboriginal Australians. Currently, there is no well-established tool to assess bronchiectasis severity specific to Indigenous peoples. Nor has the applicability and validity of the two well-established bronchiectasis severity assessment tools - The "Bronchiectasis Severity Index" (BSI) and "FACED" scale been vigorously tested in an Indigenous population. This retrospective study evaluated the validity of the BSI and FACED amongst an adult Aboriginal Australian cohort with bronchiectasis in the Top End Northern Territory (NT) of Australia.

Methods

Patients with CT confirmed bronchiectasis identified between 2011 and 2020, residing in the Top End of the NT were eligible to be enrolled. The primary endpoint of 4-year mortality was assessed via hospital records, and sensitivity and specificity of the BSI and FACED assessed against this using area under the curve (AUC) receiver operating characteristics analysis. For patients with missing data, a relative BSI / FACED score was used which divided the score recorded for that patient by the total potential score based on their available clinical data.

Results

A total of 456 adult Aboriginal Australian patients >18 years of age were included (55.5% female, median age 49 years). According to the BSI score 43.4% of patients were assessed to have mild, 30.5% moderate and 26.1% severe bronchiectasis (median score 4 (IQR 2, 8)). According to the FACED 80.9% were assessed to have mild, 17.8% moderate and 1.3% severe (median score of 1 (IQR 0, 2)). Four-year mortality was 11.2% (median age of death 55.6 years). Sensitivity and specificity of the BSI combining moderate and severe were 86.3 and 47.2% respectively, and for severe alone 51% and 77%. Sensitivity and specificity of the FACED combining moderate and severe were 21.6% and 81.2%, respectively, and for severe alone 2% and 98.8%. The AUC for the continuous total BSI was 0.703, and the FACED 0.515. Utilising a relative score, based only on data available for patients with missing data (ie lung function or BMI) resulted in slightly improved AUCs for both the BSI (0.717) and FACED (0.571).

Conclusion

Both BSI and FACED bronchiectasis assessment tools may not be ideal in an Indigenous/Aboriginal people's context. However, it may be reasonable to utilise the relative BSI score in this population until Indigenous people's specific bronchiectasis severity assessment tools are developed.

Case Report: Effects of Environmental Smoke Exposure on Respiratory Conditions-A Report of an Aboriginal Man Fire Hunting for Mud Turtles in the Top End, Northern Territory of Australia

Environmental smoke has been shown to have significant associations with both causation and exacerbation of respiratory conditions. Aboriginal Australians in the Northern Territory (NT) of Australia are disproportionately affected by respiratory illness in comparison with non-Aboriginal Australians. Traditionally, Aboriginal communities have utilized fire for multiple purposes, such as land management practices, cultural ceremonies, hunting, and cooking. In this report, we describe an Aboriginal man who presented with acute exacerbation of airway disease after environmental smoke exposure while being in the close vicinity of "fire hunting" for "mud turtles" from a Top End remote Aboriginal community in the NT of Australia. This report highlights the potential impact of nontobacco environmental smoke exposure contributing to the causation and exacerbation of chronic respiratory conditions among Aboriginal Australians. Hence, further research is warranted to address mitigating strategies in this population.

Illness perceptions in relation to self-management behaviour among elderly patients with COPD: A cross-sectional study

AIMS

The purpose of this study was to investigate the status of self-management behaviour and illness perceptions and to examine illness perceptions in relation to self-management behaviour in elderly patients with chronic obstructive pulmonary disease (COPD).

METHODS

A cross-sectional study was conducted, and 152 elderly COPD patients were recruited via the convenience sampling method. The COPD Self-Management Scale and the Revised Illness Perception Questionnaire for COPD patients were used to examine self-management behaviour and illness perceptions. Pearson correlation analysis, univariate analysis and hierarchical linear regression analysis were used to explore illness perceptions in relation to self-management behaviour.

RESULTS

The mean overall score for self-management behaviour was 2.90 ± 0.39. Among the subscales of self-management behaviour, information management had the lowest score of 2.20 ± 0.76. Patients' demographic and clinical characteristics, including educational level, smoking status, type of primary caregiver, home oxygen therapy and COPD duration, were found to be significant determinants of self-management behaviour. After controlling for these variables, several illness perception subscales, including treatment control, personal control, coherence, timeline cyclical and identity, were significantly correlated with self-management behaviour.

CONCLUSIONS

This study confirmed that elderly COPD patients' self-management behaviour was unsatisfactory and that illness perceptions were significant determinants of self-management behaviour. The findings may contribute to the development of self-management interventions for elderly COPD patients.

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.

A Qualitative Study of Aboriginal Peoples' Health Care Experiences With Chronic Obstructive Pulmonary Disease

Aboriginal Australians experience a high prevalence of chronic obstructive pulmonary disease (COPD), with high rates of potentially preventable hospitalisations. However, little is known about Aboriginal peoples' experiences of living with COPD and how they navigate health care systems. This study used thematic analysis and Aboriginal methodology to explore Aboriginal peoples' lived experiences of COPD, their health care journey from receiving a diagnosis of COPD to the clinical management, and the impact of COPD on their daily lives. We conducted in-depth semi-structured interviews over a 6-month period with 18 Aboriginal adults diagnosed with COPD from four Aboriginal Community Controlled Health Services (ACCHS) in New South Wales, Australia. Reflexive thematic analysis was employed to ensure rigour. The findings revealed deeply personal and reflective stories shaped by historical, social, and cultural realities of Aboriginal peoples living with COPD. Four themes were identified characterising their experiences. Based on the findings, the following guidance is provided on future COPD care for Aboriginal peoples: Better alignment of existing COPD management with Aboriginal peoples' cultural contexts and perspectives to improve access to culturally safe care; Increased funding for ACCHS to enhance COPD management, such as early detection through case finding and access to ACCHS-led pulmonary rehabilitation; Engaging family members in COPD management and providing culturally centred COPD education that facilitates discussions and builds health literacy and self-management skills; Implementing health promotion initiatives to increase awareness and counteract fear and shame to improve early COPD detection.

Factors influencing survival and mortality among adult Aboriginal Australians with bronchiectasis-A 10-year retrospective study

Background

The prevalence of bronchiectasis among adult Aboriginal Australians is higher than that of non-Aboriginal Australians. However, despite evidence to suggest higher prevalence of bronchiectasis among Aboriginal people in Australia, there is sparce evidence in the literature assessing clinical parameters that may predict survival or mortality in this population.

Methods

Aboriginal Australians residing in the Top End Health Service region of the Northern Territory of Australia aged >18 years with chest computed tomography (CT) confirmed bronchiectasis between 2011 and 2020 were included. Demographics, body mass index (BMI), medical co-morbidities, lung function data, sputum microbiology, chest CT scan results, hospital admissions restricted to respiratory conditions and all-cause mortality were assessed.

Results

A total of 459 patients were included, of whom 146 were recorded deceased (median age at death 59 years). Among the deceased cohort, patients were older (median age 52 vs. 45 years, p = 0.023), had a higher prevalence of chronic obstructive pulmonary disease (91 vs. 79%, p = 0.126), lower lung function parameters (median percentage predicted forced expiratory volume in 1 s 29 vs. 40%, p = 0.149), a significantly greater proportion cultured non-Aspergillus fungi (65 vs. 46%, p = 0.007) and pseudomonas (46 vs. 28%, p = 0.007) on sputum microbiology and demonstrated bilateral involvement on radiology. In multivariate models advancing age, prior pseudomonas culture and Intensive care unit (ICU) visits were associated with increased odds of mortality. Higher BMI, better lung function on spirometry, prior positive sputum microbiology for Haemophilus and use of inhaled long-acting beta antagonist/muscarinic agents may have a favourable effect.

Conclusion

The results of this study may be of use to stratify high risk adult Aboriginal patients with bronchiectasis and to develop strategies to prevent future mortality.

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.

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.

Case Report: Catastrophic Effects of Using Cannabis Via Bucket Bong in Top End Northern Territory of Australia

The prevalence of cannabis usage is increasing worldwide, including among both Indigenous and non-Indigenous Australians. The long-term effects of cannabis use on the lungs are well-known. However, the acute adverse effects on the lungs are sparsely reported. There are different ways in which cannabis can be inhaled, such as smoking or through a water vaporizing method known as a "bong." An improvised innovative bong device that is commonly used in Northern Australia, called a "bucket bong," uses water and air pressure to assist in cannabis inhalation. In this report, we describe three patients from remote and rural Northern Australian communities presenting with near-life-threatening events (acute pneumonitis and massive pneumothorax) immediately after the use of cannabis via bucket bong.

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.

Awareness of chronic obstructive pulmonary disease (COPD) among the general population in Aseer Region, Kingdom of Saudi Arabia (KSA)

Background

Chronic obstructive pulmonary disease (COPD) is a common but preventable disease and has a prevalence of 5%-14% in the general population. It is characterized by airflow limitation and persistent respiratory symptoms. In this survey, we aimed to assess the awareness of COPD among the general population in the Aseer Region of the Kingdom of Saudi Arabia (KSA).

Method

This was an observational, cross-sectional study in which predesigned electronic questionnaires were distributed to 504 randomly selected community personnel utilizing phone services. The collected data were analyzed using the IBM SPSS Statistics software, version 24 for Windows (IBM Corp., Armonk, NY).

Results

Participants were asked 11 questions with yes-or-no answers based on awareness and symptoms of COPD: 35.5% of participants had heard about the COPD as a term and 72% had no detailed information about COPD. Only 3.5% of participants had relatives with COPD. During the survey on COPD symptoms, 31% of participants chose shortness of breath and the rest chose cough (20%), sputum production (15%), wheezing (14%), and chest pain (19%). Almost two-third of the participants had no idea about COPD symptoms. For the most disease knowledge, majority of the study participants had very poor knowledge about the disease that was evident in the 22 questions intended to assess this domain. Social media sites ranked as the most popular source of information on COPD among the study participants.

Conclusion

Awareness about COPD among the general population in the Aseer Region in KSA is poor. It is advisable to carry out programs to increase their level of awareness.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.