Predictors of success and failure in pulmonary rehabilitation

The purpose of the present study was to identify prognostic features of chronic obstructive pulmonary disease (COPD) associated with success or failure in pulmonary rehabilitation. Patients were stratified according to the Medical Research Council (MRC) dyspnoea score.

A total of 74 stable COPD patients (mean +/- SD age 68 +/- 10 yrs), 21 MRC dyspnoea score grade 1/2, 29 grade 3/4 and 24 grade 5, with a mean forced expiratory volume in one second of 1.1 +/- 0.6 L, attended for rehabilitation. Assessments consisted of the following: quadriceps torque, 6-minute walking distance (6MWD), Brief Assessment Depression Cards and St George's Respiratory Questionnaire (SGRQ). Predictors of drop-out and of response (a change in SGRQ of four points or 6MWD of 54 m) were tested using binary logistic regression.

In total, 51 patients completed the study. Of these, 39 (77%) showed a clinically significant benefit in either 6MWD or SGRQ. Baseline variables were poor predictors of response in each case. Significant differences were seen between MRC dyspnoea score groups for change in 6MWD and SGRQ Score. Only grade 1/2 and 3/4 patients improved. Depression was a risk factor for subject drop-out compared with nondepressed patients.

Baseline state is a poor predictor of response to rehabilitation, although Medical Research Council dyspnoea score grade 5 patients showed smaller magnitudes of improvement than patients with less severe Medical Research Council dyspnoea score grades. Risk of drop-out is significantly greater in depressed compared with nondepressed patients.