A comparison of twice- versus once-weekly supervision during pulmonary rehabilitation in chronic obstructive pulmonary disease

OBJECTIVE: To compare the effects of twice- versus once-weekly supervised pulmonary rehabilitation on exercise capacity and quality of life in patients with chronic obstructive pulmonary disease (COPD). DESIGN: Prospective, randomized, parallel-group study. SETTING: Hospital outpatient physiotherapy department. PARTICIPANTS: Patients with COPD. INTERVENTION: Group 1 (n=46) received 1 supervised exercise session a week and 2 unsupervised sessions; group 2 (n= 45) received 2 supervised exercise sessions a week and 1 unsupervised session for 6 weeks. Patients were assessed at baseline and at 6 weeks, 2 months, and 6 months. MAIN OUTCOME MEASURES: Incremental (ISWT) and endurance (ESWT) shuttle walk tests and Chronic Respiratory Disease Questionnaire (CRDQ). RESULTS: Sixty-six of 91 patients (group 1, n=34; group 2, n=32) completed the 6-week program. There was no significant difference in key outcome measures between the 2 groups (ISWT, 13.50m; 95% confidence interval [CI], -10.06 to 37.15m; ESWT, 72.64s; 95% CI, -96.01 to 241.29s; CRDQ total score, 2.54; 95% CI, -3.16 to 8.24). The results of the ESWTs suggest there may be an interaction between baseline exercise capacity and benefit of pulmonary rehabilitation, with more disabled patients achieving greater benefit if they are supervised twice weekly. Irrespective of group, allocation benefits after pulmonary rehabilitation had almost dissipated by 6 months. CONCLUSIONS: There was no difference in the effectiveness of twice- versus once-weekly supervised pulmonary rehabilitation. This study highlights the need for development of strategies that will maintain the improvement achieved by the initial pulmonary rehabilitation program.