Association Between Inhaled Corticosteroid and Incidence of Idiopathic Pulmonary Fibrosis: Nationwide Population based Study

Abstract Idiopathic pulmonary fibrosis (IPF) is a chronic progressive disease, with the use of systemic steroids linked to poor outcomes. This study investigated the association between inhaled corticosteroids (ICS) use and IPF risk using national insurance data, particularly in individuals with chronic airway diseases. Utilising the National Health Insurance Service-National Sample Cohort database, our study included patients diagnosed with chronic obstructive pulmonary disease (COPD) or asthma. ICS exposure was assessed via treatment claims, and IPF cases were identified using broad and narrow criteria. We used inverse probability of treatment weighting (IPTW) with propensity scores for balanced covariate analysis. Of 57,456 patients, 16.5% used ICS. ICS users showed higher rates of broad (0.98 vs. 0.41 per 1,000) and narrow IPF (0.61 vs. 0.21 per 1,000) than non-users. Pre-IPTW analysis suggested an increased risk of IPF with ICS use, but this was not significant post-IPTW. However, continuous ICS dose and daily mean high-dose ICS (≥ 1000 µg/day) use showed a correlation with higher IPF risk post-IPTW. Subgroup analysis revealed an increased risk in medically aided. Our data suggested that high-dose ICS use may be associated with elevated IPF risk, especially in patients receiving medical aid.