Short- and long-term effects of outpatient rehabilitation in patients with chronic obstructive pulmonary disease: a randomized trial.

PURPOSE Pulmonary rehabilitation programs are effective in patients with severe chronic obstructive pulmonary disease (COPD) in the short term, but their long-term effects are not known. We investigated the short- and long-term effects of a 6-month outpatient rehabilitation program in patients with severe COPD. SUBJECTS AND METHODS One hundred patients were randomly assigned to receive either an exercise training program that included cycling, walking, and strength training (n = 50) or usual medical care (n = 50). Thirty-four patients in the training group were evaluated after 6 months (end of training), and 26 were evaluated after 18 months of follow-up. In the control group, 28 patients were evaluated at 6 months and 23 after 18 months. We measured pulmonary function, 6-minute walking distance, maximal exercise capacity, peripheral and respiratory muscle strength, and quality of life (on a 20 to 140-point scale), and estimated the cost-effectiveness of the program. RESULTS At 6 months, the training group showed improvement in 6-minute walking distance [mean difference (training - control) of 52 m; 95% confidence interval (CI), 15 to 89 m], maximal work load (12 W; 95% CI, 6 to 19 W), maximal oxygen uptake (0.26 liters/min; 95% CI, 0.07 to 0.45 liters/min), quadriceps force (18 Nm; 95% CI, 7 to 29 Nm), inspiratory muscle force (11 cm H(2)O; 95% CI, 3 to 20 cm H(2)O), and quality of life (14 points; 95% CI, 6 to 21 points; all P <0.05). At 18 months all these differences persisted (P <0.05), except for inspiratory muscle strength. For 6-minute walking distance and quality of life, the differences between the training group and controls at 18 months exceeded the minimal clinically-important difference. CONCLUSION Among patients who completed the 6-month program, outpatient training resulted in significant and clinically relevant changes in 6-minute walking distance, maximal exercise performance, peripheral and respiratory muscle strength, and quality of life. Most of these effects persisted 18 months after starting the program.