8-Foot-Up-and-Go Test is Associated with Hospitalizations and Mortality in Idiopathic Pulmonary Fibrosis: A Prospective Pilot Study

Abstract

Purpose: To assess the prognostic value of the 8-foot-up-and-go test (8-FUGT) in pilot cohort of patients with idiopathic pulmonary fibrosis (IPF). Methods: Thirty-four patients with IPF (68 ± 8 years) underwent 8-FUGT at baseline and were followed for up to 40 months. Receiver operating characteristics and age-adjusted Cox hazard ratios (HR) were analyzed for 8-FUGT, hospitalizations, and mortality. Correlation coefficients were determined between 8-FUGT and other exercise tests. Results: 8-FUGT ≥ 6.9 s was found to be associated with hospitalization (sensitivity = 77%, specificity = 76%, p = 0.03) and mortality (sensitivity = 91%, specificity = 70% p = 0.008) in patients with IPF. Categorical models demonstrated that 8-FUGT ≥ 6.9 s was associated with 14.1- (p < 0.001) and 55.4-fold (p = 0.001) increased risks for hospitalization and mortality, respectively. In continuous models, for every 1-s slower performance in the 8-FUGT there were 54% [HR = 1.54, 95% CI (1.11–2.15) p = 0.01] increased risk for hospitalization and 94% [HR = 1.94, 95% CI (1.26–2.99) p = 0.003] increased risk for mortality. 8-FUGT was inversely related to 6-min walk distance (r = − 0.61), peak oxygen consumption (r = − 0.58), and peak work rate (r = − 0.72), all p < 0.001. Conclusions: The 8-FUGT was strongly associated with hospitalizations and mortality in patients with IPF, as well as correlated with established prognostic markers. These novel findings suggest a prognostic value of the 8-FUGT for risk stratification, referral to pulmonary rehabilitation, and considering listing for lung transplantation. 8-FUGT is an inexpensive and practical tool that has prospective for implementation in clinical and research settings in IPF. Future prospective studies should evaluate the effect of changes in 8-FUGT on clinical outcomes. Trial registration: NCT01499745, Clinicaltrials.gov.