Effects of pulmonary rehabilitation on exercise capacity in patients with COPD: a number needed to treat study

BACKGROUND: Pulmonary rehabilitation (PR) is recognized as an evidence-based treatment in improving dyspnea and quality of life in patients with COPD. We evaluated the number needed to treat (NNT) to achieve an increase in physical capacity, as defined by a significant improvement in the six-minute walk test (6MWT) in patients with COPD undergoing PR. METHODS: The study enrolled 284 patients aged 41 to 86 years (mean age 69.4 years) divided into two groups: a study group (222 patients) undergoing a PR program, and a control group (62 patients) treated only with drugs. The study group included patients with COPD divided in four subgroups according to GOLD stages. RESULTS: In the study group, 142 out of 222 patients (64%) had an increase of at least 54 m in the 6MWT following PR versus 8 out of 62 patients (13%) in the control group after the same time interval. The NNT in the overall study group was 2; the same NNT was obtained in GOLD stages 2, 3, and 4, but was 8 in stage 1. CONCLUSIONS: PR is highly effective in improving the exercise capacity of patients with COPD, as demonstrated by a valuable NNT, with better results in patients with a more severe disease.