Disparities in Antifibrotic Medication Utilization Among Veterans With Idiopathic Pulmonary Fibrosis

Abstract

Two antifibrotic medications, pirfenidone and nintedanib, are approved for the treatment of idiopathic pulmonary fibrosis (IPF). Little is known about their real-world adoption. What are the real-world antifibrotic utilization rates and factors associated with uptake among a national cohort of veterans with IPF? This study identified veterans with IPF who received care either provided by the Veterans Affairs (VA) Healthcare System or non-VA care paid for by the VA. Patients who had filled at least one antifibrotic prescription through the VA pharmacy or Medicare Part D between October 15, 2014, and December 31, 2019, were identified. Hierarchical logistic regression models were used to examine factors associated with antifibrotic uptake, accounting for comorbidities, facility clustering, and follow-up time. Fine-Gray models were used to evaluate antifibrotic use by demographic factors, accounting for the competing risk of death. Among 14,792 veterans with IPF, 17%received antifibrotics. There were significant disparities in adoption, with lower uptake associated with female sex (adjusted OR, 0.41; 95%CI, 0.27-0.63; P< .001), Black race (adjusted OR, 0.60; 95%CI, 0.49-0.73; P< .001), and rural residence (adjusted OR, 0.88; 95%CI, 0.80-0.97; P= .012). Veterans who received their index diagnosis of IPF outside the VA were less likely to receive antifibrotic therapy (adjusted OR, 0.15; 95%CI, 0.10-0.22; P< .001). This study is the first to evaluate the real-world adoption of antifibrotic medications among veterans with IPF. Overall uptake was low, and there were significant disparities in use. Interventions to address these issues deserve further investigation.