Patient characteristics at baseline
| Intervention group | Control group | |
| Subjects | 300 | 302 |
| Age years | 57.7±8.2 | 57.9±6.6 |
| Female | 112 (37.3) | 101 (33.4) |
| BMI kg·m−2 | 26.6±6.4 | 26.9±6.6 |
| FEV1 L | 1.55±0.57 | 1.50±0.56 |
| FEV1 % pred | 51.0±15.3 | 49.5±15.0 |
| PImax kPa | 6.73±2.39 | 6.69±2.19 |
| GOLD stage | ||
| II | 154 (51.3) | 142 (47.0) |
| III | 114 (38.0) | 124 (41.1) |
| IV | 32 (10.7) | 36 (11.9) |
| GOLD category | ||
| A | 11 (3.7) | 7 (2.3) |
| B | 61 (20.3) | 68 (22.5) |
| C | 14 (4.7) | 16 (5.3) |
| D | 214 (71.3) | 211 (69.9) |
| Current smoker | 118 (39.3) | 115 (38.1) |
| Never-smoker | 7 (2.3) | 8 (2.6) |
| Pack-years | 39.6±23.6 | 41.8±24.0 |
| Patients with LTOT | 42 (14.0) | 56 (18.5) |
| Rehabilitation after hospitalisation due to AECOPD | 90 (30.0) | 99 (32.9) |
| BDI | 6.1±2.6 | 5.8±2.5 |
Data are presented as n, mean±sd or n (%). BMI: body mass index; FEV1: forced expiratory volume in 1 s; PImax: maximal inspiratory pressure; GOLD: Global Initiative for Chronic Obstructive Lung Disease; LTOT: long-term oxygen therapy; AECOPD: acute exacerbations of chronic obstructive pulmonary disease; BDI: baseline dyspnoea index.