Predictors of Success of Inpatient Pulmonary Rehabilitation Program in COPD Patients

Pulmonary rehabilitation programs (PR) are an important part of the comprehensive treatment of patients with chronic pulmonary diseases. Patients respond individually to PR. The aim of this study is to identify potential predictors of success of PR to recognise patients who benefit most and to uncover possible reasons for poor response to PR.

We included 121 patients with chronic obstructive pulmonary disease (COPD) who completed our 4-week inpatient PR without any exacerbations of disease during PR that could potentially affect PR outcomes. Improvement in distance of ≥30 m on the 6-minute walk test (6MWT) after PR was chosen as a primary marker of physical success. Ninety-one patients achieved improvement of ≥30 m on the 6MWT and were thus considered good responders, and 30 patients were poor responders with improvement in the distance of <30 m on the 6MWT.

We compared baseline clinical characteristics, medication, lung function, physical capacity, body composition, and laboratory blood tests between groups of good and poor responders. The most prominent differences between groups were associated with differences in baseline body composition and erythrocyte-related parameters. Good responders had significantly lower body water content (p = 0.042) and higher body weight (p = 0.036), body fat content (p = 0.049), dry lean mass (p = 0.021), haemoglobin levels (p = 0.040), erythrocyte count (p = 0.017), haematocrit (p = 0.030) and iron level (p = 0.028).

A more muscular body composition and a higher ability to transport oxygen from the blood to the muscles could be beneficial for the outcome of PR.