C | YC | PC | NC | p-value | |||||
C versus YC | NC versus YC | C versus PC | NC versus PC | PC versus YC | |||||
Subjects | 1012 | 65 | 78 | 263 | |||||
General characteristics | |||||||||
Age, years, mean±sd, median (interquartile range) | 67.8±9.9, 68.0 (59.0–75.0) | 45.8±2.6, 46.0 (43.0–48.0) | 63.5±11.6, 65.0 (54.0–72.0) | 59.3±10.1, 59.0 (51.0–67.0) | <0.0001 | <0.0001 | 0.003 | 0.0002 | <0.0001 |
Females | 418 (41.3%) | 30 (46.2%) | 44 (56.4%) | 163 (62.0%) | 0.44 | 0.02 | 0.009 | 0.37 | 0.22 |
BMI, kg·m−2 | 27.4±4.6 | 27.4±7.0 | 28.0±4.8 | 26.7±4.5 | 0.88 | 0.49 | 0.31 | 0.06 | 0.52 |
Smoking status | 0.004 | <0.0001 | 0.009 | 0.59 | 0.0002 | ||||
Active smokers | 301 (29.7%) | 32 (49.2%) | 14 (17.9%) | 58 (22.1%) | |||||
Former smokers | 433 (42.8%) | 20 (30.8%) | 31 (39.7%) | 90 (34.2%) | |||||
Never-smokers | 278 (27.5%) | 13 (20%) | 33 (42.3%) | 115 (43.7%) | |||||
Smoking exposure, pack-years | 29.2±30.1 | 22.2±21.35 | 18.5±25.6 | 13.1±17.9 | 0.06 | 0.0005 | 0.002 | 0.04 | 0.35 |
Education level | 0.15 | 0.03 | 0.23 | 0.27 | 0.56 | ||||
No studies | 41 (4.1%) | 0 | 1 (1.3%) | 2 (0.8%) | |||||
Primary education | 270 (26.7%) | 14 (21.5%) | 17 (21.8%) | 52 (19.8%) | |||||
Secondary education | 243 (24.0%) | 19 (29.3%) | 17 (21.8%) | 45 (17.1%) | |||||
University or vocational training | 454 (44.9%) | 31 (47.7%) | 42 (53.8%) | 164 (62.4%) | |||||
Clinical characteristics | |||||||||
mMRC dyspnoea scale | 0.14 | 0.0009 | 0.32 | <0.0001 | 0.01 | ||||
Grade 0 | 499 (49.2%) | 42 (64.6%) | 30 (38.5%) | 223 (84.8%) | |||||
Grade 1 | 355 (35.1%) | 18 (27.7%) | 36 (46.2%) | 36 (13.7%) | |||||
Grade 2 | 113 (11.2%) | 3 (4.6%) | 9 (11.5%) | 3 (1.1%) | |||||
Grade 3 | 39 (3.9%) | 2 (3.1%) | 3 (3.8%) | 1 (0.4%) | |||||
Grade 4 | 6 (0.6%) | 0 | 0 | 0 | |||||
CAT | 9.1±6.8 | 9.1±6.4 | 11.3±6.1 | 5.7±5.1 | 0.98 | <0.0001 | 0.004 | <0.0001 | 0.03 |
Cough and phlegm# | 621 (66.3%) | 37 (58.7%) | 78 (100.0%) | 70 (28.0%) | 0.21 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
Asthma | 163 (16.1%) | 19 (29.2%) | 5 (6.4%) | 24 (9.1%) | 0.006 | <0.0001 | 0.02 | 0.45 | 0.0003 |
Charlson Comorbidity Index | 0.7±1.1 | 0.6±1.7 | 0.5±0.9 | 0.3±0.8 | 0.71 | 0.01 | 0.22 | 0.01 | 0.63 |
COTE index | 1.2±2.4 | 1.4±2.8 | 1.7±2.8 | 0.9±2.1 | 0.44 | 0.12 | 0.10 | 0.01 | 0.62 |
Exacerbations last year | 114 (11.3%) | 5 (7.7%) | 2 (2.6%) | 9 (3.4%) | 0.37 | 0.12 | 0.01 | 0.70 | 0.15 |
Treatments | |||||||||
Any respiratory treatment | 641 (63.3%) | 28 (43.1%) | 39 (50.0%) | 86 (32.7%) | 0.001 | 0.11 | 0.01 | 0.005 | 0.40 |
Treatment with short-acting β-agonist | 251 (24.8%) | 17 (26.2%) | 4 (5.1%) | 8 (3.0%) | 0.80 | <0.0001 | <0.0001 | 0.37 | 0.0004 |
Treatment with anticholinergics | 159 (15.7%) | 4 (6.2%) | 2 (2.6%) | 5 (1.9%) | 0.03 | 0.06 | 0.001 | 0.71 | 0.28 |
Treatment with inhaled corticosteroids | 189 (18.7%) | 10 (15.4%) | 4 (5.1%) | 9 (3.4%) | 0.50 | 0.0002 | 0.002 | 0.48 | 0.03 |
Data are presented as mean±sd or n (%), unless otherwise stated. BMI: body mass index; mMRC: modified Medical Research Council; CAT: COPD Assessment Test; COTE: COPD-specific comorbidity test. #: European Coal and Steel Community questionnaire.