Multi-institutional prospective cohort study of prognostic factors in patients with idiopathic pulmonary fibrosis receiving long-term oxygen therapy

Rationale: Despite a lack of beneficial evidence in idiopathic pulmonary fibrosis (IPF), long-term oxygen therapy (LTOT) is currently prescribed for many patients with IPF. Little is known about clinical course of them. Aim: To clarify the overall survival and prognostic factors of IPF patients after prescription of LTOT. Method: A prospective cohort multicenter study, enrolling patients with IPF who started LTOT between December 1, 2012 and November 30, 2015 from 21 institutes in Japan. The decision for starting LTOT depended on each site. Clinical data at starting LTOT and three-year follow-up data including death and cause of death were studied. Results: 147 eligible patients were recruited. 117 were male and the mean (SD) age was 71.2 (8.1) years. The mean (SD) percentage predicted FVC was 61.7 (15.6)%. 111 (76%) died with a median follow-up of 479 days. Causes of death were chronic respiratory insufficiency in 52%, acute exacerbation in 27%, and lung cancer in 5%. The median survival from starting LTOT was 537 days. By COX univariate analysis, low FVC, high COPD assessment test (CAT) score, resting hypoxemia (SpO2 This study was partially supported by a grant to the Diffuse Lung Diseases Research Group from the Ministry of Health, Labor and Welfare, Japan.