Outcomes of a pulmonary rehabilitation program in chronic obstructive pulmonary disease

Abstract

Results of pulmonary rehabilitation programs (PRP) are evaluated using patient-centered outcomes. Since patient-centered outcomes (exercise capacity and quality of life) can be largely subjective, we hypothesized that they may fit to different subgroups of COPD patients. We studied 81 COPD patients (58 males; 70.0±7.6 years; FEV1 1.17±0.44 L, 47.3±15.4% predicted), attending an outpatient PRP. After a baseline evaluation (anthropometrics, Medical Research Council – MRC – dyspnea score, pulmonary function test – PFTs, 6-minute walk test – 6MWT, cardiopulmonary exercise test – CPET, Saint George Respiratory Questionnaire –SGRQ, BODE index), results of the PRP were evaluated according to the minimal important difference (MID) for 6MWT and SGRQ. We had 4 groups based on PRP results: group 1: concordant negative (none MID reached; 24% of whole sample); group 2: concordant positive (both MID reached, 18.7%); group 3: discordant SGRQ (MID for SGRQ only reached, 37.3%); group 4: discordant 6MWT (MID for 6MWT only reached, 20%). The 4 groups did not differ for anthropometrics, PFTs, CPET, while group 4 showed higher BODE index and MRC scores and lower exercise capacity than groups 1 and 3. In conclusion, 6MWT could be more useful in evaluating PRP benefits in more severe patients (according to both baseline symptoms and exercise capacity), while SGRQ may better perform in patients with mild-to-moderate impairment.