Epidemiology of idiopathic pulmonaryfibrosis: a population registry-based study

Background Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive respiratory rare disease characterized byan irreversible loss of lung function, with unknown etiology and poor prognosis.Methods A population registry-based study was conducted to provide estimates of prevalence, incidence andsurvival of IPF. The study included all cases diagnosed with IPF in the years 2000–2022 and residing in Tuscany, Italy.Prevalence as of December 31, 2022, was calculated by sex and age class. Incidence was calculated across the period2018–2022. Survival at 1, 5 and 10 years from diagnosis with 95% confidence intervals (CI) was estimated by sexand age class using the Kaplan-Meyer method. The independent effect of sex and age at diagnosis on survival wasestimated by Cox proportional hazard model.Results A total of 1,388 subjects with IPF were diagnosed during the study period. The prevalence as of 31stDecember 2022 was 21.5 cases (95%CI: 20.0–23.0) per 100,000 inhabitants, with a significantly higher frequency inmen and in 70–79 years age group (p < 0.0001). The average annual incidence was 4.6 cases per 100,000 inhabitants,with significantly higher incident cases among males (p < 0.0001). Survival at 1, 5 and 10 years from diagnosis was91.3%, 51.4% and 22.2%, respectively. Women exhibited a longer survival than men (34.8% vs. 17.3% at 10 years),while patients under 70 had the highest survival rate at 58.2% (95% CI: 52.5–63.4) at five years. Cox regression modelconfirmed a higher risk of mortality for men (adjusted Hazard Ratio – adjHR = 1.52, 95%CI: 1.25–1.84, p < 0.0001) andwith age at diagnosis (adjHR = 1.04, 95%CI: 1.03–1.05, p < 0.0001).Conclusions The higher prevalence and incidence rates of IPF among men, as indicated by this population registry-based study, align with recent data reported in Europe. Furthermore, IPF is consistently identified as a disease with apoor prognosis, especially in male patients. Therefore, early and accurate diagnosis, coupled with timely management,is essential to improve the care and treatment outcomes for these patients.