Purpose: Pulmonary rehabilitation (PR) improves exercise tolerance in patients with chronic obstructive pulmonary disease. However, it is unclear why some patients do not improve quality of life during a training program. Our objective was to evaluate the differences between patients with chronic obstructive pulmonary disease who improve and those who do not improve quality of life during a pulmonary rehabilitation program.
Methods: Seventy-three patients underwent a PR program. All patients trained at 80% (legs) and 50% (arms) of their maximum load. Incremental and endurance tests, 6-min walk test, and health-related quality of life with the St George Respiratory Questionnaire (SGRQ) were measured. We subdivided the groups based on a decrease ≥4 points in the pre- and post-PR SGRQ total score (G1); <4-point change in the SGRQ total score (G2); and an increase in scores ≥4 points (G3).
Results: Exacerbation frequency (P = .004) and SGRQ total scores (P < .001) were lower in G1 and G2 than in G3. G1 (P = .0007) and G2 (P = .0005) significantly improved 6-min walk test distance. Before PR, G1 and G2 walked greater distances than G3 (P = .003); however, the difference was no longer significant after PR (P = .34). A significant load increase was seen after PR for the 3 groups (P < .05). We found a significant correlation between the SGRQ and the Charlson index (r = 0.78, P < .0001), exacerbation frequency (r = 0.72, P < .0001), and basal dyspnea index (r = -0.48, P < .0001).
Conclusion: Patients whose quality of life did not improve after comprehensive PR presented a higher number of disease-related exacerbations with comorbidities.