Bronchiectasis among Australian Aboriginal and non-Aboriginal patients in the regional and remote population of the Northern Territory of Australia.

INTRODUCTION Chronic respiratory disorders are highly prevalent among Australian Aboriginal people living in the Top End Health Service region in the Northern Territory, Australia. Bronchiectasis is a heterogenous disease that features among these chronic respiratory conditions in this population. However, there are sparse comparative data between Aboriginal and non-Aboriginal patients with bronchiectasis from this region. METHODS In this retrospective study, demographics, clinical characteristics and relevant laboratory parameters were compared among adult Aboriginal and non-Aboriginal patients diagnosed with bronchiectasis between 2012 and 2017. RESULTS A total of 388 adults had radiology-confirmed bronchiectasis and 258 (66%) were Aboriginal. Compared to non-Aboriginal patients, Aboriginal patients were significantly younger (mean age 54 v 67 years), the majority lived in rural and remote communities (80% v 9 %), had higher rates of self-reported smoking (52% v 19%), alcohol consumption (29% v 12%) and co-occurrence of chronic obstructive pulmonary disease (65% v 38%) and other chronic co-morbidities. Sputum microbiology was also different between the groups with Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis being more common in Aboriginal patients, while Pseudomonas aeruginosa, Aspergillus species and non-tuberculous mycobacteria were higher in non-Aboriginal patients. Further, Aboriginal patients had poorer lung function compared to non-Aboriginal patients (forced expiratory volume after 1 second predicted 33% v 53%, forced vital capacity predicted 49% v 60% respectively), higher exacerbation rates (29% v 18%) and poorer overall outcomes (age at death 60 v 76 years). CONCLUSION Within a single health service, Aboriginal patients with bronchiectasis have significantly poorer outcomes with differing manifestations and higher comorbidities than non-Aboriginal patients. This warrants further studies to identify feasible interventions to reduce this inequity.