Linear regression coefficient analysis with chronic obstructive pulmonary disease severity score total score as a dependent outcome variable#
| Regression coefficient (95% CI) | p-value | |
| FEV1 % pred | −0.024 (−0.040– −0.009) | 0.002 |
| Number of exacerbations | 0.946 (0.0793–1.099) | <0.001 |
| MRC dyspnoea grade | 2.703 (2.391–3.016) | <0.001 |
| Charlson index | 0.391 (0.222–0.561) | <0.001 |
| Constant | 4.447 (3.331–5.584) | <0.001 |
CI: confidence interval; FEV1: forced expiratory volume in one second; % pred: percentage of the predicted value; MRC: UK Medical Research Council. #: n = 827.