Epidemiology of Pulmonary Fibrosis : A Cohort Study Using Healthcare Data in Sweden

Introduction: Data on the epidemiology of idiopathic pulmonary fibrosis (IPF) in Sweden are lacking. This study estimates the incidence and prevalence of IPF in Sweden, and describes the demographic and clinical characteristics and the overall survival of patients with IPF. Methods: Two cohorts were studied: a national cohort of 17,247 patients with pulmonary fibrosis (ICD-10 code J84.1 with no competing diagnosis) from the Swedish National Patient Register (cohort 1 [C1]); and an electronic medical record-based regional subset of C1 comprising 1755 patients having pulmonary fibrosis and a radiology procedure (C2). Results: The incidence of pulmonary fibrosis in C1 ranged from 10.4 to 15.4 cases per 100,000 population per year between 2001 and 2015. The prevalence increased from 15.4 to 68.0 cases per 100,000 population per year. Patients C 70 years and men had a higher incidence and prevalence of pulmonary fibrosis. Common comorbidities included respiratory infections and cardiovascular disorders. Approximately one-third of patients in each cohort were hospitalised with pulmonary fibrosis within a year of diagnosis. The median survival time from disease diagnosis was 2.6 years in C1 and 5.2 years in C2. Older patients had a higher risk of hospitalisation and mortality. Women had a better prognosis than men. Conclusion: This study underscores the importance of pulmonary fibrosis as a cause of respiratory-related morbidity and mortality in Sweden. The stable incidence and increasing prevalence over time suggests longer survival. The higher morbidity and mortality in older patients highlights the importance of early case detection, diagnosis and management for better prognosis