Predictors of response to pulmonary rehabilitation in stable chronic obstructive pulmonary disease patients: A prospective cohort study

CONTEXT: Pulmonary rehabilitation (PR) has become a standard of care in the management of chronic obstructive pulmonary disease (COPD). However, a significant proportion of the patients do not show benefit after the PR program. AIMS: The study was planned to find different patient- and/or disease-related factors that may predict response to PR in stable COPD. SUBJECTS AND METHODS: A total of 102 stable COPD patients were prospectively enrolled. Baseline evaluation and investigations, including spirometry, arterial blood gas analysis, and bone mineral density assessment, were done. Thereafter, all patients underwent an 8-week comprehensive outpatient PR program that consisted of exercise training, education, nutritional, and psychological counseling. The response to PR was dichotomously (yes/no) defined by the combined improvement in exercise tolerance (6-min walk distance [6MWD] +54 m) and quality of life (St. George's Respiratory Questionnaire [SGRQ] score - 4 points) measured before and after the program. Thereafter, different predefined factors were analyzed for their possible association with the PR response. RESULTS: A total of 80 patients (78.4%) completed the PR program and were subjected for analysis. Out of them, 42 (52.5%) showed improvement in both 6MWD and SGRQ score (46 in 6MWD and 54 in SGRQ score). After application of multivariate logistic regression analysis, forced expiratory volume in 1 s <50% predicted (odds ratio [OR]: 2.9; 95% confidence interval [CI]: 1.1–8.3; P = 0.04) and osteoporosis (OR: 0.26; 95% CI: 0.13–0.53; P < 0.001) were found as independent factors predicting PR efficacy. CONCLUSIONS: Poor baseline lung function predicts a short-term improvement in exercise capacity and quality of life in COPD patients, whereas osteoporosis is a negative predictor of PR response. Active search for these factors may help in better patient selection, thus leading to improved outcome after PR.