Epidemiology and survival of idiopathic pulmonary fibrosis from national data in Canada

Idiopathic pulmonary fibrosis (IPF) is a rare disease, with estimates of prevalence varying considerably across countries due to paucity in data collection. The aim of this study was to investigate the prevalence and incidence of IPF in Canada using administrative data requiring minimal extrapolation.We used mandatory national administrative data from 2007-2011 to identify IPF cases of all ages with an International Classification of Diseases (Version 10, Canadian) diagnosis code of J84.1. We used a broad definition that excluded cases with subsequent diagnosis of other interstitial lung diseases, and a narrow definition that required further diagnostic testing prior to IPF diagnosis. We explored survival and quality of life.For all ages, the broad prevalence of IPF was 41.8 per 100 000 (14 259 cases) and was higher for men. The incidence rate was 18.7 per 100 000 (6390 cases) and was higher for men. The narrow prevalence was 20.0 per 100 000 (6822 cases) and incidence was 9.0 per 100 000 (3057 cases). The 4-year risk of death was 41.0% and the quality of life with IPF after 2 years was lower than for Global Initiative for Chronic Obstructive Lung Disease stage IV chronic obstructive pulmonary disease.Using comprehensive national data, the prevalence of IPF in Canada was higher than other national estimates, suggesting that either IPF may be more common in Canada or that data capture may have been previously limited.