Why carry out this study?

Treatment options for chronic fibrosing ILDs with a progressive phenotype other than idiopathic pulmonary fibrosis are limited, with a high unmet need

The epidemiology of these diseases has not been widely investigated

This claims database study estimates their incidence and prevalence in the USA

What was learned from the study?

The estimated age- and sex-adjusted prevalence per 100,000 persons of fibrosing ILD (95% confidence interval) was 117.82 (116.56, 119.08) and of chronic fibrosing ILDs with a progressive phenotype was 70.30 (69.32, 71.27)

The estimated incidence per 100,000 patient-years of fibrosing ILD was 51.56 (50.88, 52.24) and of chronic fibrosing ILDs with a progressive phenotype was 32.55 (32.01, 33.09)

This is the first such study to provide estimates of prevalence and incidence of these diseases and could form the groundwork for future studies