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

Abstract

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.

Idiopathic pulmonary fibrosis: another step in understanding the burden of this disease

“…However, it is also possible that precise codes in these datasets may not capture all cases of IPF. One study from Italy reported a higher incidence of IPF after review of additional case records than when using coding criteria alone [15], yielding a very similar result for the narrow case definition to that obtained by HOPKINS et al [12] in the current study.…”

“…Nevertheless, accepting potential variation in clinical practice and coding, the application of a specific ICD-10 code clearly suggests a fibrotic interstitial lung disease that may well be IPF or something very similar, and this was more common in the study by HOPKINS et al [12] than many other studies. This may reflect missed cases elsewhere, but the fact that some studies have taken a similar approach and still yielded lower incidences [22,23] suggests there may well be true differences in IPF incidence across regions.…”

“…The study by HOPKINS et al [12] provides other insights. The authors estimated the prevalence of IPF, and found this to be 41.8 cases per 100 000 (broad definition) and 20.0 cases per 100 000 (narrow definition).…”

“…In this issue of the European Respiratory Journal, HOPKINS et al [12] add to the literature with their study of IPF in Canada. The authors used two data sources to identify cases: a mandatory nationwide database of hospital admissions, and a smaller database of emergency department and outpatient clinic attendances covering ∼50% of the national population.…”

Toward understanding patient experience in idiopathic pulmonary fibrosis

“…Based on a recent systematic review [2], global IPF incidence is 3-9 cases per 100 000 per year in Europe and North America with increasing incidence over time. A similar incidence, 9 cases per 100 000, was reported in Canada using a narrow definition of IPF [3]. The age-adjusted mortality rate for IPF ranges from 2 to 10 per 100 000, resulting in an estimated 30 000-60 000 deaths in Europe in 2014 [4].…”