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

BACKGROUND AND OBJECTIVE: Poor lung function is a predictor of future all-cause mortality. In Australia, respiratory diseases are particularly prevalent among the Indigenous population, especially in remote communities. However, there are little published pulmonary function tests (PFT) data of remote-based adult Indigenous patients. We aimed to evaluate the severity of airflow obstruction and other PFT abnormalities of adults referred to specialist respiratory clinics in remote Indigenous communities.

METHODS: Retrospective analysis of PFTs [pre- and post-bronchodilator spirometry, total lung capacity (TLC) and diffusing capacity to carbon monoxide (DLCO)] of Indigenous patients collected during specialist respiratory clinics in remote Northern Territory (NT) Indigenous communities (Australia) between 2013-2015. The National Health and Nutrition Examination Survey (NHANES) III without ethnic correction was used as the reference.

RESULTS: Of the 357 patients, 150 had acceptable spirometry and 71 had acceptable DLCO and TLC studies. Despite the relatively young age (mean=49 years, SD=12.9) their lung function was generally low; mean % predicted values were FEV1 =55%(SD=20.5%), FVC=61%(SD=15.6%), DLCO=64.0%(SD=19.7%), TLC=70.1%(SD=18.2%). Mean FEV1 /FVC ratio was preserved (0.71, SD=0.16). Post-bronchodilator airflow obstruction (FEV1 /FVC<0.7) was found in 37% of patients, where a large proportion (67%) demonstrated at least severe airflow obstruction with a mean FEV1 of 41% predicted.

CONCLUSION: In this first study of PFT findings of Indigenous adults from a remote-based clinical service, we found a high rate of at least moderate airflow limitation and low FVC along with preserved FEV1/FVC ratio. Increased awareness and screening for reduced lung function needs to be considered in this population. This article is protected by copyright. All rights reserved.