Healthcare expenditure and its socio-demographic and clinical predictors in Australians with poorly controlled asthma

INTRODUCTION: Asthma has substantial and increasing health and economic burden worldwide. This study aimed to estimate healthcare expenditure and determine the factors that increase expenditure in Australians with poorly controlled asthma. METHODS: Individuals ≥18 years of age with poorly controlled asthma, as determined by a score ≥1.5 on the Asthma Control Questionnaire, were included in the study. Healthcare utilization costs from medical services and medications were estimated over an average follow-up of 12 months from administratively linked data: the Medicare Benefits Schedule and Pharmaceutical Benefits Scheme. A generalized linear model with gamma distribution and log link was used to predict participants’ key baseline characteristics associated with variations in healthcare costs. RESULTS: A total of 341 participants recruited through community pharmacies were included. The mean (standard deviation, SD) age of participants was 56.6 (SD 17.6) years, and approximately 71% were females. The adjusted average monthly healthcare expenditure per participant was $AU386 (95% CI: 336, 436). On top of the average monthly costs, an incremental expenditure was found for each year increase in age ($AU4; 95% CI: 0.78, 7), being unemployed ($AU201; 95% CI: 91, 311), one unit change in worsening quality of life ($AU35; 95% CI: 9, 61) and being diagnosed with depression and anxiety ($AU171; 95% CI: 36, 306). CONCLUSIONS: In a cohort of Australian patients, characterized by poor asthma control and co-morbidities individuals impose substantial economic burden in terms of Medicare funded medical services and medications. Programs addressing strategies to improve the quality of life and manage co-morbid anxiety and depression and encourage asthma patients’ engagement in clinically tolerable jobs, may result in significant cost savings to the health system.