Introduction Most patients with COPD are elderly, and the presence of co-morbidities is not uncommon. Co-morbidities are an important determinant of health related quality of life in patients with COPD. Although pulmonary rehabilitation (PR) is well known to improve exercise performance, health-related quality of life and symptoms, a proportion of patients are non-responders. We hypothesised that improvement in exercise capacity and health-related quality of life following PR may be limited in the presence of co-morbidities.
Methods A structured history was taken from 128 patients referred to an 8-week supervised outpatient PR programme. Individuals' self-reported co-morbidities were assessed by the Charlson index, which assigns to each disease a score that is proportional to the disease related risk of death. The calculated Charlson index did not include COPD in the individual's score as suggested in the original description. In 115 patients completing the programme, changes in incremental shuttle walk (ISW) and chronic respiratory disease questionnaire (CRQ) domains following PR were calculated, and compared between those patients with and without co-morbidities (Charlson index 1 or more vs 0) using unpaired t-test or non-parametric equivalent.
Results 84 patients (73%) had a Charlson index of 1 or more. No difference in age, gender, FEV1, or MRC Dyspnoea score was seen between those with and without co-morbidities. Mean (SD) change in ISW following PR was not significantly different between those with and without co-morbidities (63 (96) vs 33 (88); p=0.13). Similarly there were no significant differences in CRQ-D change (4.1 (6.4) vs 5.7 (7.1); p=0.26), CRQ-F change (2.6 (5.1) vs 4.4 (5.7); p=0.13), CRQ-E change (3.6 (7.8) vs 6.4 (7.7); p=0.09) or CRQ-M change (2.7 (4.8) vs 2.3 (6.9); p=0.75). No association was seen between Charlson index and change in ISW following PR (Spearman rank=0.09; p=0.32).
Discussion The prevalence of co-morbidities in COPD patients undergoing PR is high. The presence of co-morbidities does not seem to affect patients' response to pulmonary rehabilitation.