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

Abstract

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. 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. 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 (DLCO) 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\u2009=\u20090.15 [95% CI 0.10–0.20]; zFVC\u2009=\u20090.25 [0.20, 0.31]), and FEV1/FVC% significantly reduced (mean\u2009=\u2009\u2009−\u20090.10 [95%CI\u2009−\u20090.07 to\u2009−\u20090.03]), with no significant change in DLCO. Patients with COPD had lower FEV1 improvement, whilst underweight and obese patients had lower FVC improvement. 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.