Pulmonary rehabilitation in COPD according to global initiative for chronic obstructive lung disease categories

Abstract

BACKGROUND: Pulmonary rehabilitation (PR) programs are a mainstay for treatment in COPD. Lung function impairment alone does not predict beneficial effects of PR. The new COPD categories take into account assessment of symptoms, such as dyspnea and exacerbations, which may be important indications for PR. This study evaluates the effect of PR on exercise capacity, symptoms, and health status in different COPD categories. METHODS: Subjects with COPD referred for PR were classified into COPD categories A, B, C, and D. Exercise capacity (6-min walk distance [6MWD] and constant work rate at 80% of peak work rate), symptoms (Mahler’s index), and health status (St George Respiratory Questionnaire) were compared before and after PR programs for each COPD category. Changes were analyzed using generalized estimating equations and logistic regression models. RESULTS: One hundred sixty-seven subjects were included (COPD categories A [16%], B [12%], C [31%], and D [41%]). Groups were homogeneous in age, body mass index, smoking pack-years, and comorbidities. Significant improvements in all outcomes were found after adjusting for COPD categories, age, sex, body mass index, and COPD-specific comorbidity index. All COPD categories improved exercise capacity (6MWD and constant work rate). Categories A and C had more pronounced improvements in 6MWD than categories B and D. Symptoms (Mahler’s index) also improved significantly in categories A and C, whereas change was not significant in categories B and D. Global health status (St George Respiratory Questionnaire) improved significantly in all COPD categories. Despite these differences, the odds of achieving a minimum clinically important difference in each outcome were similar and without statistical significance for the A, B, and C categories when compared with D. CONCLUSIONS: This study demonstrates that patients in all COPD categories may improve exercise capacity, symptoms, and health status with PR programs, and COPD categories alone may not be sufficient to discriminate which patients may benefit most from them.