An epidemiological study on the effect of age, sex and comorbidities on the clinical course of idiopathic pulmonary fibrosis

Abstract

Background: The natural history of Idiopathic Pulmonary Fibrosis (IPF), in terms of survival and hospitalization frequency, has been rarely investigated in real life. Even more scarce are evidences about how age, sex and comorbidities could affect such history. Objective: To describe the course of IPF in an unselected sample of cases from Northern Italy and to evaluate how demographic characteristics and patient complexity could affect mortality and hospitalization frequency after the onset Methods: We performed a retrospective observational study using administrative databases: we identified incident IPF cases from 2005 to 2010 based on hospitalizations and outpatient visits, and we traced their healthcare accesses and vital status up to December 31st 2010. We evaluated demographic and clinical characteristics at onset. We assessed the effect of sex, age and Charlson Comoridity Index (CCI) on survival and time to first hospitalization through Cox proportional hazard models. Results: The study population consisted of 2093 incident cases (60% males). The proportion of males with at least one chronic comorbidity was higher than that observed in females (75% vs 64%). Age, sex and CCI affected the risk of death and hospitalization: hazard ratio (HR) was higher in males and increased with age and CCI. However, only sex was associated with the risk of hospitalization for causes related to IPF: HR in males was 1.3 (95%CI: 1.1;1.5) as compared to females. Conclusions: Our study, based on real-life data, confirmed that the risks of death and hospitalization are high in IPF patients, and that age, sex, and comorbidities play a role in the clinical course of the disease