Mortality-Reducing Effect of Rehabilitation for COPD: Observational Propensity-Matched Cohort Study Using a Nationwide Database

BACKGROUND: In the course of therapy of patients with COPD, non-pharmacologic treatment, such as rehabilitation, plays an important role. Although some studies have provided concrete evidence of the effectiveness of rehabilitation in improving functional outcomes in subjects with COPD, evidence of its mortality-reducing effect has been insufficient. In the present study, we examined whether rehabilitation had positive effects on in-hospital mortality of subjects with COPD. METHODS: We used the Japanese Diagnosis Procedure Combination nationwide administrative claims database. This was a retrospective cohort study, and there were 18,037 eligible subjects with COPD from 1,055 hospitals. The main outcome was in-hospital mortality rates. A one-to-one propensity score matching method was used to compare hospital mortality rates after admission between rehabilitation and non-rehabilitation groups. RESULTS: A total of 3,356 pairs of subjects were selected from the rehabilitation and non-rehabilitation groups (n = 6,712). Subjects in the rehabilitation program showed a reduction in the odds of mortality (odds ratio = 0.80, 95% CI 0.65-1.00, P = .045). In the subgroup analyses, the rehabilitation group had a lower in-hospital mortality in the pre-obese subgroup (body mass index 25.0-29.9) than the non-rehabilitation group (P = .02). Although not significant, the rehabilitation group showed a relatively low in-hospital mortality in the Hugh-Jones dyspnea scale class 5 subgroup (P = .066). CONCLUSIONS: This large nationwide cohort study showed that rehabilitation indeed contributed to a reduction of in-hospital mortality. These findings underscore the importance of adopting rehabilitation as part of the treatment of COPD.