Minimal clinically important difference in Barthel dyspnoea after pulmonary rehabilitation in patients with Chronic Obstructive Pulmonary Disease

Background and Aim: The Barthel Dyspnoea Index (BDi) is responsive to change in patients with chronic obstructive pulmonary disease (COPD). However, the minimum clinically important difference (MCID) has not been established. We aimed to identify the MCID for the BDi using anchor-based and distribution-based methods. Methods: In a retrospective analysis we assessed BDi before and after inpatient pulmonary rehabilitation in 2328 patients with COPD (1152 with chronic respiratory failure - CRF). The Medical Research Council (MRC) score was measured concurrently as anchors. We used receiver operating characteristic (ROC) curves, linear regression, and distribution-based methods to estimate the MCID for the BDi; we included only patients with paired BDi scores in the analysis. Results: The mean change for the whole group in BDi score with pulmonary rehabilitation was -10 (IQR -17 : -3; p Conclusions: The most conservative estimate of the MCID for the BDi is -9 points in patients with COPD and -12 in patients without CRF. This estimate could be useful in the clinical interpretation of BDi data, particularly in response to intervention studies.