Response to Letter to the Editor on "Effectiveness of Continuous Chest Wall Vibration With Concurrent Aerobic Training on Dyspnea and Functional Exercise Capacity in Patients With Chronic Obstructive Pulmonary Disease: A Randomized Controlled Trial".

OBJECTIVE:To investigate the effects of continuous chest wall vibration with concurrent aerobic training in addition to a 4-week pulmonary rehabilitation program on dyspnea and functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD). DESIGN:Randomized, single-blind, placebo-controlled trial. SETTING:The Cardiopulmonary Rehabilitation Unit of a tertiary referral subacute rehabilitation center. PARTICIPANTS:A sample of 146 consecutive patients with COPD (Global Initiative for Chronic Obstructive Lung Disease II-III-IV) were assessed for eligibility. The final sample of 40 patients (N=40) was randomized into 3 groups (intervention, sham intervention, control). INTERVENTIONS:All groups carried out 5 sessions per week for 4 weeks of standard pulmonary rehabilitation treatment. The 2 daily 30-minute sessions included aerobic training and resistance training or airway clearance techniques. The intervention group performed the aerobic training with the addition of continuous chest wall vibration applied during cycling, whereas the sham intervention group received continuous chest wall vibration as a placebo during cycling. MAIN OUTCOME MEASURES:Six-minute walk distance (6MWD) and Barthel Index based on dyspnea (BID). RESULTS:A total of 36 participants completed the study (69±7 years; forced expiratory volume in 1 second percentage of predicted, 40.15%±15.97%). Intention to treat analysis showed no significant differences between groups for 6MWD and BID. However, the increase in 6MWD was a clinically important difference in the intervention group (42.57±43.87m, P=.003), with a moderate effect size (d=0.58). CONCLUSIONS:Continuous chest wall vibration with concurrent aerobic training in addition to a standard pulmonary rehabilitation program might improve functional exercise capacity compared with usual care, but there were no effects on dyspnea, respiratory muscle function, or quality of life in patients with COPD.