The comparison of different dyspnoea scales in patients with COPD

(i) To compare the relationship between different dyspnoea scales and physical and clinical parameters of patients with chronic obstructive pulmonary disease (COPD); and (ii) to determine the most suitable scale among these scales for this patient group.

Forty patients with COPD [mean 1st second forced expiratory volume (FEV(1)), 49.16 +/- 2.33% predicted], aged 53-85 participated in this study. The severity of dyspnoea was assessed with different five scales [Modified Borg Scale (MBS), Visual Analogue Scale (VAS), Medical Research Council Dyspnoea Scale (MRCS), Baseline Dyspnoea Index (BDI) and Oxygen Cost Diagram (OCD)]. As clinical parameters, respiratory function was measured by means of pulmonary function test and arterial blood gas analysis. As physical parameters, age and body mass index was recorded.

Patient's dyspnoea severities were 1.59 +/- 2.75, 2.03 +/- 2.82, 2.14 +/- 1.44, 6.81 +/- 4.07, 4.56 +/- 2.47 for MBS, VAS, MRCS, BDI, OCD, respectively (P = 0.08). It was proven that only %FEV(1) had a correlation with MRCS (r = -0.67, P = 0.01) and BDI (r = 0.58, P = 0.02). In addition to these determinations MRCS, MBS and VAS had a strong correlation defining their relationships with each other (P < 0.05).

MRCS and BDI could assess dyspnoea during daily activities, so these scales showed strength correlation with physical and clinical values. Briefly MRCS is the most suitable dyspnoea scale for the patients with COPD, moreover, BDI, as the second suitable scale, is correlated only with MRCS. Based on these findings, we recommended that MRCS and BDI are appropriate scales for evaluation of dyspnoea in the patients with COPD.