Table 1.
Demographic and clinical characteristics of the sample. N=7,810 (COPD stage was reported for 7,004 patients)
| Demographic variables | Total sample N=7,810 | Stage I n=473 (6.7%) | Stage II n=3,408 (48.6%) | Stage III n=2,434 (34.8%) | Stage IV n=689 (9.8%) | Spearman's Correlation coefficient | Mantel-Haenszel Chi-square test | p |
|---|---|---|---|---|---|---|---|---|
| Age mean (SD) | 69 (9.1) | 67.5 (11.3) | 68.3 (9.6) | 70.1 (8.6) | 69.3 (8.4) | 0.08 | <0.001 | |
| Gender, n (%) | ||||||||
| Men | 3,448 (44.1%) | 228 (48.2%) | 1,511 (44.3%) | 1,067 (43.8%) | 322 (46.7%) | 0.067 | 0.796 | |
| Women | 4,362 (55.9%) | 245 (51.8%) | 1,897 (55.7%) | 1,367 (56.2%) | 367 (53.3%) | |||
| Marital status n=5,154, n (%) | ||||||||
| Living alone | 1,934 (38.5%) | 81 (31.0%) | 746 (34.7%) | 696 (41.4%) | 211 (44.3%) | 61.013 | <0.001 | |
| Co-habiting | 3,083 (61.5%) | 181 (69.0%) | 1,406 (65.3%) | 983 (58.5%) | 265 (55.7%) | |||
| Clinical variables | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | |||
| FEV% of predicted value | 50.3 (20.1) | 85.1 (38.6) | 59.2 (9.2) | 38.5 (6.6) | 23.4 (5.2) | −0.88 | <0.001 | |
| Saturation | 95.48 (2.7) | 96.7 (1.7) | 96.2 (2.1) | 95.1 (2.6) | 93.7 (3.3) | −0.33 | <0.001 | |
| Exacerbations during the past 12 months | 0.78 (1.4) | 0.44 (1.1) | 0.55 (1.1) | 0.88 (1.4) | 1.5 (2.1) | 0.22 | <0.001 | |
| Hospital admissions the past 12 months | 0.23 (0.8) | 0.06 (0.4) | 0.11 (0.6) | 0.25 (0.7) | 0.59 (1.4) | 0.22 | <0.001 | |
| Body mass index (BMI) | 26.0 (5.6) | 26.0 (5.2) | 26.7 (5.3) | 25.6 (5.8) | 24.0 (5.7) | −0.15 | <0.001 | |
| Patient-reported variables | n (%) | n (%) | n (%) | n (%) | n (%) | |||
| Smoking non-smoker | 243 (3.5%) | 21 (4.4%) | 119 (3.5%) | 82 (3.4%) | 21 (3.1%) | |||
| Have quit smoking | 4,240 (60.7%) | 264 (55.9%) | 1,955 (57.5%) | 1,537 (63.3%) | 484 (70.9%) | 33.440 | <0.001 | |
| Still smoking | 2,501 (35.8%) | 187 (39.6%) | 1,325 (39.0%) | 811 (33.4%) | 178 (26.1%) | |||
| Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | Mean (SD) | ||||
| Exercise capacity, days per week | 3.3 (2.8) | 3.8 (2.7) | 3.6 (2.7) | 3.2 (2.8) | 2.27 (2.6) | −0.12 | <0.001 | |
| Functional dyspnoea (MRC) | 1.88 (1.2) | 1.21 (1.0) | 1.48 (1.1) | 2.18 (1.2) | 2.97 (1.1) | 0.39 | <0.001 | |
| Quality of life according to CCQ | 1.8 (1.2) | 1.4 (1.1) | 1.5 (1.0) | 2.05 (1.2) | 2.7 (1.2) | 0.33 | <0.001 | |
Spearman's correlation coefficient is presented between continuous variables and stage.