The economic burden of idiopathic pulmonary fibrosis in Australia: a cost of illness study.

purposeIdiopathic pulmonary fibrosis (IPF) is a type of interstitial lung disease found mostly in elderly persons, characterized by a high symptom burden and frequent encounters with health services. This study aimed to quantify the economic burden of IPF in Australia with a focus on resource utilization and associated direct costs.

methodsParticipants were recruited from the Australian IPF Registry (AIPFR) between August 2018 and December 2019. Data on resource utilization and costs were collected via cost diaries and linked administrative data. Clinical data were collected from the AIPFR. A "bottom up" costing methodology was utilized, and the costing was performed from a partial societal perspective focusing primarily on direct medical and non-medical costs. Costs were standardized to 2021 Australian dollars ($).

resultsThe average annual total direct costs per person with IPF was $31,655 (95% confidence interval (95% CI): $27,723-$35,757). Extrapolating costs based on prevalence estimates, the total annual costs in Australia are projected to be $299 million (95% CI: $262 million-$338 million). Costs were mainly driven by antifibrotic medication, hospital admissions and medications for comorbidities. Disease severity, comorbidities and antifibrotic medication all had varying impacts on resource utilization and costs.

conclusionThis cost-of-illness study provides the first comprehensive assessment of IPF-related direct costs in Australia, identifies the key cost drivers and provides a framework for future health economic analyses. Additionally, it provided insight into the major cost drivers which include antifibrotic medication, hospital admissions and medications related to comorbidities. Our findings emphasize the importance of the appropriate management of comorbidities in the care of people with IPF as this was one of the main reasons for hospitalizations.