Incidence, Prevalence, and Survival of Patients with Idiopathic Pulmonary Fibrosis in the UK

Recent developments in the care of patients with idiopathic pulmonary fibrosis have the potential to improve survival rates. Population-based estimates of the current disease burden are needed to evaluate the future impact of newly approved therapies. The objective of this study is to describe incidence, prevalence, and survival of idiopathic pulmonary fibrosis patients in the UK. Between 2000 and 2012, a patient cohort (N = 9,748,108), identified from Clinical Practice Research Datalink primary care data, was used to identify incident and prevalent cases of idiopathic pulmonary fibrosis-clinical syndrome. Incident cases were followed up to identify deaths. Poisson and Cox regressions were used to calculate incidence rate ratios (IRR) and hazard ratios for mortality, respectively. Adjustments were made for age, gender, and strategic health authority. Survival from diagnosis was estimated using Kaplan-Meier analysis. In total 1491 and 4527 incident cases were identified using narrow and broad idiopathic pulmonary fibrosis-clinical syndrome definitions, respectively. Incidence and prevalence increased during the study. Compared with 2000, a near 80% increase in incidence was observed by 2012 [IRR 1.78 (95% CI 1.50-2.11; broad definition)], despite an observed decrease using the narrow definition [0.50 (0.38-0.65)]. Median survival was 3.0 years (95% CI 2.8-3.1) and 2.7 years (95% CI 2.5-3.0) in broad (n = 2168) and narrow case sets (n = 996), respectively. No significant changes in survival were observed. Idiopathic pulmonary fibrosis incidence rates have increased since 2000 and survival remains poor. These results provide a benchmark against which the effects of future treatment changes can be measured. InterMune UK and Ireland (now part of F. Hoffman La Roche).