Subjects n | Disease severity | p-value | |||
Mild (MRC grade 1/2) | Moderate (MRC grade 2/3) | Severe (MRC grade 5) | |||
6MWD % pred of normative values | 51 | 7.8±6.5 | 10.0±11.3 | 5.2±11.9 | 0.003 |
6MWD m | 51 | 54.7±45.0 | 68.0±74.2 | 32.6±74.8 | 0.002 |
Quadriceps torque Nms | 51 | 1.6±19.6 | 3.1±33.8 | 6.5±18.7 | ns |
SGRQ score# | 51 | -7.5±10.3 | -7.0±8.4 | 0.7±11.2 | 0.03 |
MIP % pred | 48 | 11.1±22.9 | 2.7±10.3 | 1.9±10.5 | ns |
MEP % pred | 49 | -0.0±22.7 | 10.1±17.9 | 11.3±31.5 | ns |
Grip % pred | 51 | -0.9±11.4 | 3.1±12.3 | -0.6±19.8 | ns |
COPDSE | 49 | 0.4±0.5 | 0.1±0.9 | 0.1±0.7 | ns |
LCADL# | 51 | -0.4±3.9 | -1.1±7.5 | 0.7±8.5 | ns |
Data are presented as mean difference±sd between follow-up and baseline. A positive score = improvement, unless otherwise indicated (#: negative score = improvement). p-values represent the significance of disease severity in a generalised linear model with score at follow-up as the dependent variable, disease severity as the independent variable and baseline score as a covariate (nonsignificant (ns) = p>0.05). MRC: Medical Research Council; 6MWD: 6-minute walk distance; SGRQ = St George's Respiratory Questionnaire; MIP: maximal inspiratory pressure; MEP: maximal expiratory pressure; COPDSE: Chronic Obstructive Pulmonary Disease Self-Efficacy Scale; LCADL: London Chest Activity of Daily Living Scale.