Therapeutic validity and effectiveness of supervised physical exercise in patients with COPD - A systematic review and meta-analysis

Background: In patients with COPD the effects of physical exercise on exercise capacity seem only modest and the type, dose and duration of exercise training to optimize exercise capacity unclear. Up until now no specific attention has been given to the therapeutic validity of physical exercise training programs. Aims: Our aim was to determine the effectiveness of supervised physical exercise training in patients with COPD taken into consideration indices such as therapeutic validity of the interventions, methodological quality of studies and exercise volume. Methods: RCTs comparing supervised exercise training with usual care were identified. Therapeutic validity of exercise training and methodological quality of included studies were assessed. Overall effects were calculated using a random effects model for maximal and endurance exercise capacity. Results: 12 RCTs involving 613 patients with COPD were included. Significant differences in maximal exercise capacity (SMD 0.72, 95% CI 0.45-0.96) and endurance exercise capacity (SMD 0.82, 95% CI 0.56-1.08) in favour of supervised physical exercise training were found. Surprisingly, overall effects were not significantly influenced by methodological quality of included studies, therapeutic validity of the interventions, exercise volume per week, or total exercise volume. Conclusion: Supervised physical exercise training for patients with COPD increases both maximal and endurance exercise capacity. The optimal type, dose and duration of physcial exercise training however remains unclear and probably needs further thorough in depth meta-analysis of the clustered data of all the here included trials.