Demographic characteristics of the study population
| Characteristics | Overall | IG | CG |
| n=67 | n=33 | n=34 | |
| Age (years), mean (SD) | 64.3 (7.7) | 66.1 (6.8) | 62.7 (8.2) |
| Sex (female), n (%) | 33 (49.3) | 16 (48.5) | 17 (50.0) |
| BMI (kg/m2), mean (SD) | 24.4 (5.1) | 25.0 (4.7) | 23.8 (5.6) |
| Current smoker, n (%) | 8 (11.9) | 3 (9.1) | 5 (14.7) |
| Smoking in the past, n (%) | 58 (86.6) | 30 (90.9) | 28 (82.4) |
| Never smoker, n (%) | 1 (1.5) | 0 (0.0) | 1 (2.9) |
| Exacerbation in the last 12 months, n (%) | 53 (79.1) | 29 (87.9) | 24 (70.6) |
| Number of exacerbations treated as outpatient in the past 12 months, mean (SD) | 1.19 (1.14) | 1.19 (1.33) | 1.19 (0.87) |
| Number of exacerbations treated as inpatient in the past 12 months, mean (SD) | 1.08 (1.23) | 1.21 (1.50) | 0.91 (0.79) |
| Long-term oxygen therapy, n (%) | 40 (59.7) | 18 (54.5) | 22 (64.7) |
| FEV1 (L) (mean (SD)) | 1.27 (0.50) | 1.31 (0.53) | 1.23 (0.46) |
| FEV1% predicted (mean (SD)) | 44.0 (16.2) | 45.5 (14.5) | 42.6 (17.8) |
| FEV1% FVC, mean (SD) | 0.52 (0.14) | 0.54 (0.14) | 0.50 (0.15) |
| FVC% predicted, mean (SD) | 64.8 (18.4) | 63.9 (17.9) | 65.7 (19.2) |
| CAT (points), mean (SD) | 16.3 (7.09) | 16.5 (7.2) | 16.0 (7.1) |
| GOLD stage II, n (%) | 20 (29.9) | 10 (30.3) | 10 (29.4) |
| GOLD stage III, n (%) | 29 (43.3) | 17 (51.5) | 12 (35.3) |
| GOLD stage IV, n (%) | 18 (26.9) | 6 (18.2) | 12 (35.3) |
BMI, body mass index; CAT, COPD Assessment Test; CG, control group; FEV1, forced expiratory volume in 1 s ; FVC, forced vital capacity; GOLD, Global Initiative for Obstructive Lung Disease; IG, intervention group;