Hospitalization Rates in Interstitial Lung Disease: An Analysis of the Pulmonary Fibrosis Foundation Registry.

Little is known about hospitalization in other types of interstitial lung disease (ILD) besides idiopathic pulmonary fibrosis (IPF). To determine the frequency of hospitalizations in various types of ILD and elucidate the association of hospitalization with outcomes. An analysis of the Pulmonary Fibrosis Foundation Patient Registry data was performed. Inpatient hospitalization rates and survival posthospitalization were compared for various types of ILD. Hospitalization rates were similar across ILD types: 40.6% of participants with IPF, 42.8% of participants with connective tissue disease-related ILD (CTD-ILD), 44.9% of participants with non-IPF idiopathic interstitial pneumonia (IIP), 46.5% of participants with chronic hypersensitivity pneumonitis (CHP), and 53.3% of participants with "other" ILD. All-cause hospitalization was not associated with decreased transplant-free survival (adjusted hazard ratio [AHR], 1.20; 95% confidence interval [CI] = 0.98, 1.46;  = 0.0759) after adjusting for comorbidities and severity of illness; however, respiratory-related hospitalization was (AHR, 1.53; 95% CI = 1.23, 1.90;  = 0.0001). Participants with CTD-ILD (HR, 0.43; 95% CI = 0.25, 0.75;  = 0.0031) and non-IPF IIP (HR, 0.3; 95% CI = 0.15, 0.58;  = 0.005) had a lower risk of death posthospitalization compared with those with IPF, whereas those with chronic hypersensitivity pneumonitis (HR, 0.67; 95% CI = 0.37, 1.20;  = 0.1747) or other ILD (HR, 0.54; 95% CI = 0.19, 1.54;  = 0.25) had a risk comparable with that for IPF. Rates of hospitalization are similar across ILD subtypes. The risk of death or transplant after posthospitalization is lower in patients with CTD-ILD and non-IPF IIP, compared with patients with IPF. In a mixed population of participants with ILD, all-cause hospitalizations were not associated with decreased transplant-free survival; however respiratory-related hospitalizations were.