The increasing secondary care burden of idiopathic pulmonary fibrosis: Hospital admission trends in England from 1998 to 2010

Background: The lack of mandatory clinical registries for idiopathic pulmonary fibrosis (IPF) has meant a reliance on routine clinical data to provide trends in disease incidence. Death certificate and primary care data suggest that the incidence of IPF has increased in the United Kingdom at a rate of approximately 5% per year, but due to possible concerns about the diagnostic validity of these clinical datasets, it is helpful also to analyze data from secondary care. We used national secondary care data to determine trends in hospital admissions for IPF clinical syndrome (IPF-CS) in England between 1998 and 2010. Methods: We obtained the annual number of hospital admissions for all National Health Service (NHS) hospital trusts in England for the International Classification of Diseases and Related Health Problems, 10th Revision codes J84.1 and J84.9 between 1998 and 2010. We calculated annual admission-rate ratios, adjusting for age and sex, using Poisson regression. We also investigated changes in age at admission and length of stay, and we estimated hospitalization costs. Results: The number of hospital admissions from IPF-CS increased at an annual rate of approximately 5%, from 5,524 patients in 1998 to 9,525 patients in 2010, and was highest in men and the older population. Mean age at admission increased from 66 to 71 years, while length of stay decreased by 2.1 days during the same period. Conclusions: Hospital admissions for IPF-CS in England follow a similar trend to other data sources in the United Kingdom. This has resulted in escalating costs of inpatient care, which is a significant financial burden on health-care resources.