Predictors of change in exercise capacity after comprehensive COPD inpatient rehabilitation.

BACKGROUND: In order to evaluate the factors associated with change in exercise capacity after comprehensive inpatient Pulmonary Rehabilitation (IPR) we studied 132 consecutive adults with Chronic Obstructive Pulmonary Disease (COPD) recovering from an acute exacerbation. MATERIAL/METHODS: Lung function, arterial blood gases, and respiratory muscle strength were measured at baseline. Perceived breathlessness (B), 6-minute walk distance (6MWD), dyspnea at rest and post-exertion (D), hospital anxiety and depression (HAD), and health-related quality of life were assessed before (T0) and after (T1) IPR. The patients were divided into two groups depending on the change in 6MWD: Improvers (IM at least +54 meters after IPR, n=81) or Non-Improvers (NIM, less than 54 meters or no change, n=51). RESULTS: At T1 61\% of the patients showed improvement as here defined. The IM group showed lower 6MWD and higher B and resting-D at T0 than NIM (p<0.05). A stepwise multiple regression analysis was performed using 6MWD change as the dependent variable. and anthropometric and physiological measures at T0 as the independent variables. This regression model explained 26\% of the 6MWD-change; 6MWD and PaO2 significantly contributed to this model. CONCLUSIONS: In COPD patients recovering from an acute exacerbation, the predicted change in exercise capacity using anthropometric, demographic, clinical, and physiological variables after 2 weeks of comprehensive IPR is likely to be low. The baseline level of exercise performance and arterial oxygenation show the most consistent correlation with change in walking ability in these patients.