The likelihood of improving physical activity after pulmonary rehabilitation is increased in patients with COPD who have better exercise tolerance.

Abstract

Pulmonary rehabilitation (PR) enhances exercise tolerance in patients with COPD; however, improvements in physical activity (PA) are not guaranteed. This study explored the relationship between baseline exercise tolerance and changes in PA after PR. Patient data from prospective clinical trials in the PR settings of Athens and Leuven (2008-2016) were analyzed. Validated PA monitors were worn for 1 week before and after a 12-week program. The proportion of patients who improved PA levels ≥1,000 steps/day ("PA responders") after PR was compared between those with initial 6-minute walk distance [6MWDi] <350 m and ≥350 m. Baseline predictors of PA change were evaluated via univariate and multivariate logistic regression analyses. Two hundred thirty-six patients with COPD (median [IQR] FEV1 44 [33-59] % predicted, age 65±8 years, 6MWDi 416 [332-486] m) were included. The proportion of "PA responders" after PR was significantly greater in those with higher vs lower 6MWDi (37.9% vs 16.4%, respectively; P<0.001). 6MWDi group classification was the strongest baseline independent predictor of PA improvement (univariate OR 3.10, 95% CI 1.51-6.36). The likelihood of improving PA after PR is increased with greater 6MWDi. Baseline exercise tolerance appears as an important stratification metric for future research in this field.