Clinical predictors of the efficacy of a pulmonary rehabilitation programme in patients with COPD

Summary 

Objectives

To identify predictors of success for an 8week pulmonary rehabilitation programme (PRP) in patients with chronic obstructive pulmonary disease (COPD).

Methods

Sixty patients were stratified in subgroups according to baseline findings: airway obstruction (FEV₁ ≥ or <50% pred), pulmonary hyperinflation (TLC > or ≤120% pred), BMI value (BMI > or ≤25), cardiovascular (CV) comorbidity, and resting PaO₂ (PaO₂ ≥ or <60mmHg). Outcome measurements of PRP were: >54m increase in 6min walking test (6MWT), or >4points reduction in total score of S. George Respiratory Questionnaire (SGRQ). Logistic regression analysis was used.

Results

After PRP there was a significant improvement in exercise tolerance and quality of life, which correlated with baseline FEV₁/VC, PaO₂, SpO₂, 6MWT and SGRQ. SGRQ significantly decreased and 6MWT significantly increased after PRP in all subgroups, except for patients with CV comorbidities. Both univariate and multivariate logistic regression analyses showed that BMI>25 and resting PaO₂<60mmHg were independent predictors of PRP efficacy in terms of improvement of 6MWT, but not of SGRQ scores.

Conclusions

Clinical and functional baseline findings do not predict the response to PRP in COPD. The greater efficacy in patients with BMI>25 or with PaO₂<60mmHg may be due to a greater deconditioning in overweight patients, and to a larger room for improvement in hypoxemic patients.

Keywords: COPD, Comorbities, Pulmonary rehabilitation, Predictors, 6MWT, SGRQ