FIGURE 1.

Plots showing baseline correlation between the modified Medical Research Council (mMRC) dyspnoea scale, Baseline Dyspnoea Index (BDI), COPD Assessment Test (CAT) and Clinical COPD Questionnaire (CCQ). a–c) Box and whisker plots of mMRC versus a) BDI, b) CCQ and c) CAT, where BDI, CCQ and CAT have been represented by mMRC grade. Data are presented as median and interquartile range (box) with minimum and maximum values (whiskers). Diamonds indicate mean values and circles indicate outliers. d–f) Scatterplots of d) BDI versus CAT, e) BDI versus CCQ and f) CAT versus CCQ. Spearman's rank correlation coefficient (r_s) values are indicated. COPD: chronic obstructive pulmonary disease.