Increased Mortality in Patients with Corticosteroid-Dependent Asthma: A Nationwide Population-Based Study

Abstract

Background: Chronic systemic corticosteroid (CS) therapy is associated with an increased risk of mortality in patients with many chronic diseases. However, it has not been elucidated whether chronic, systemic CS therapy is associated with increased mortality in patients with asthma. The aim of this study was to determine effects of chronic, systemic CS therapy on long-term mortality in adult patients with asthma. Methods: A population-based matched cohort study of men and women aged 18 years or older with asthma was performed using Korean National Health Insurance Service database from 2005 to 2015. Hazard ratio (HR) with 95% confidence interval (CI) for all-cause mortality among patients in CS-dependent cohort (CS use > 6 months during baseline period) relative to those in CS-independent cohort (CS use < 6 months during baseline period) was evaluated. Findings: The baseline cohort included 466,941 patients with asthma, of whom 8,334 were CS-dependent and 456,607 were CS-independent. After 1:1 matching, 8,334 subjects with CS-independent asthma were identified. The HR of mortality associated with CS-dependent asthma relative to CS-independent asthma was 2·17 (95% CI, 2·04-2·31). In patients receiving low-dose CS, HR was 1·84 (95% CI, 1·69-2·00), and that for those receiving high-dose CS was 2·56 (95% CI, 2·35-2·80). Interpretation: In this real-world, clinical practice, observational study, chronic use of systemic CS was associated with increased risk of mortality in patients with asthma, with a significant dose-response relationship between systemic CS use and long-term mortality. Funding: Korea Ministry of Environment (MOE) as the Environmental Health Action Program (2016001360003). Declaration of Interest: All authors have no conflict of interest to disclose. Ethical Approval: This study was approved by Institutional R 340 eview Board of Hanyang University Hospital (IRB number: HYUH 2017-09-051). The requirement of informed consent from participants was waived because NHIS database was constructed after anonymization.