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

Purpose: 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.
Materials and Methods: 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.
Results: Two hundred thirty-six patients with COPD (median [IQR] FEV ₁ 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).
Conclusion: 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.
Competing Interests: Disclosure CRO was the recipient of a European Respiratory Society fellowship, grant number LTRF 2014-3132. ZL was the recipient of a European Respiratory Society Fellowship, grant number LTRF 2016-6686 and is a postdoctoral fellow of the FWO-Flanders (Fellowship number 12U5618N). HD was the recipient of a joint ERS/SEPAR Fellowship (LTRF 2015-5099) and is a postdoctoral research fellow of the FWO-Flanders (12H7517N). FMR was supported by The National Council for Scientific and Technological Development (CNPq), Brazil (249579/2013-8). TT is supported by the Flemish Research Foundation (FondsWetenschappelijk Onderzoek), grant number FWO G·0871·13. The authors report no other conflicts of interest in this work.