Clinical and economic burden of idiopathic pulmonary fibrosis in Quebec, Canada

BACKGROUND: Idiopathic pulmonary fibrosis (IPF), although rare, is a severe and costly disease. OBJECTIVE: To estimate the clinical and economic burden of IPF over multiple years before and after diagnosis using comprehensive administrative databases for the province of Quebec, Canada. METHODS: Several administrative databases from Quebec, providing information on hospital care, community care, and pharmaceuticals, were linked over a 5-year period ending March 31, 2011, which was before approval of antifibrotic drugs in Canada. Prevalent and incident IPF cases were defined using International Classification Disease-10-CA codes and International Classification Disease-9-CM codes. 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 to confirm IPF diagnosis. Incident cases had an IPF code in a particular year without any IPF code in the 2 previous years. Health care resource utilization before and after the index diagnosis date was determined and costs calculated. Costs were expressed in 2016 Canadian dollars. RESULTS: Over 5-years, 10,579 (mean age: 76.4; 58% male) satisfied the broad definition of IPF and 8,683 (mean age: 74.5; 57% male) satisfied the narrow definition (82% of broad). Incidences of IPF overall were 25.8 and 21.7/100,000 population for broad and narrow definitions, respectively. Three-year survival was 40% and 37% in broad and narrow cohorts, respectively. For both cohorts, health care resource utilization and costs increased several years before diagnosis ($2,721 and $7,049/patient 5 years and 2 years prior to diagnosis using a broad definition, respectively) and remained elevated for multiple years post diagnosis ($12,978 and $8,267 at 2 and 3 years postdiagnosis). CONCLUSION: Health care resource utilization and costs of IPF increase many years prior to diagnosis. Incorporating multiyear annual costs before and after diagnosis results in a higher estimate of the economic burden of IPF than previous studies using a 1-year time frame.