Duration of pulmonary rehabilitation to achieve a plateau in quality of life and walk test in COPD

OBJECTIVE: To address the minimum duration of pulmonary rehabilitation necessary for patients with chronic obstructive pulmonary disease (COPD) to achieve a plateau in Health-Related Quality of Life (HRQL) and exercise tolerance. METHODS: COPD patients with a dyspnea rating of at least 2 on the Medical Research Council scale participated in an outpatient rehabilitation program of 3 weekly sessions for 12 weeks. Measurements included HRQL and exercise tolerance 2 weeks before the program started and every 2 weeks thereafter. Patients were considered to have reached a plateau if they showed no improvement beyond 20% of the minimal important difference between 2 consecutive evaluations on HRQL score or walk tests. RESULTS: Twenty-eight patients participated. The number of patients achieving stability after 8 weeks, showing continued improvement after 8 weeks, and demonstrating an erratic pattern of change was as follows: for physical function 16 (56%), 10 (37%) and 2 (7%) patients; for emotional function 22 (79%), 5 (18%) and 1 (4%); and for 6-min walk test 21 (75%), 5 (18%) and 2 (7%). More severe patients demonstrated a greater likelihood (76%) of achieving stability in physical function at 12 weeks than did less severe patients (27%; p on difference=0.003). The likelihood of stability at 12 weeks in emotional function and the 6-min walk test did not differ by severity. CONCLUSIONS: A program of 3 weekly 3-h sessions of outpatient pulmonary rehabilitation program should last at least 8 weeks in order to achieve optimal HRQL and exercise tolerance for most patients.