Investigation of clinical predictors of survival in idiopathic pulmonary fibrosis patients: A cohort study in Taiwan

Abstract

Background: Two antifibrotic medications, pirfenidone and nintedanib, have been approved as treatments for idiopathic pulmonary fibrosis (IPF)-a life-threatening interstitial lung disease. However, there are insufficient current data regarding clinical predictors of survival for patients with IPF in the era of antifibrotics.

Methods: We retrospectively analyzed the medical records of patients with IPF treated between April 2017 and May 2020. Univariate and multivariate Cox proportional hazard models were used to identify independent predictors of mortality among these patients with IPF.

Results: A total of 40 patients with IPF (average age, 75.58 ± 8.34 years) were included in the study, 27 (67.5%) of whom were treated with antifibrotic drugs. In the entire cohort, 14 (35%) patients died, and the overall survival of the study population was 48.52 ± 5 months (median, not applicable [NA] [29-NA] months). The univariate and multivariate Cox proportional hazard models indicated that chest tightness, finger clubbing, acute exacerbation after medication, decreased percentage forced vital capacity (%FVC), and decreased percentage 1-second forced expiratory volume were clinical factors linked to all-cause mortality among all patients, although without statistical significance at the multivariate level. Meanwhile, only finger clubbing was a significant mortality predictor among patients who received antifibrotic medications. A mortality scoring system was built upon the aforementioned risk factors, with the exclusion of %FVC, whose individual mortality score was nearly zero.

Conclusion: Chest tightness, finger clubbing, acute exacerbation after medication, and decreased %FVC were clinical factors associated with mortality in patients with IPF, although without statistical significance. A scoring system including these factors can be used to predict all-cause mortality in patients with IPF. The mere intake of antifibrotic medications was not a significant mortality predictor in this study. This might be owed to the retrospective nature of the study, where many patients started the medications after the deterioration of their pulmonary function rather than from the start.