Table 1.
Demographic, clinical characteristics and questionnaires’ scores
| Variable | Overall population (N=497) | Composite event (no) (n=194) | Composite event (yes) (n=303) | P-value |
|---|---|---|---|---|
| Sex, male | 446 (89.7%) | 171 (88.1%) | 273 (90.0%) | 0.970 |
| Age (years) | 68.7 (9.2) | 67.4 (9.3) | 69.5 (9.1) | 0.011 |
| Body mass index (kg/m2) | 27.4 (5.0) | 27.3 (5.2) | 27.4 (4.9) | 0.961 |
| Active smokers | 147 (29.6%) | 70 (36.1%) | 77 (25.4%) | 0.061 |
| Smoking habits (packs-years) | 52.7 (30.5) | 54.3 (27.7) | 53.5 (32.1) | 0.913 |
| Cardiovascular risk | ||||
| None | 133 (26.7%) | 54 (27.8%) | 79 (26.1%) | 0.581 |
| Increased | 127 (25.5%) | 48 (24.7%) | 79 (26.1%) | |
| High | 107 (21.5%) | 36 (18.6%) | 71 (23.4%) | |
| Very high | 124 (24.9%) | 52 (28.8%) | 72 (23.7%) | |
| Missing data | 6 (0.01%) | 4 (0.02%) | 2 (0.01%) | |
| Diabetes mellitus | 132 (26.6%) | 63 (32.4%) | 69 (22.7%) | 0.117 |
| Waist circumference (cm) | 99.0 (18.6) | 98.3 (19.9) | 99.4 (17.7) | 0.490 |
| Time walking per day (minutes) | 62.8 (88.0) | 65.2 (80.4) | 61.1 (92.8) | 0.621 |
| Time of COPD evolution (years) | 10.2 (8.5) | 9.7 (9.5) | 10.6 (7.7) | 0.282 |
| Number of exacerbations in the previous year | 2.9 (2.6) | 2.3 (1.9) | 3.3 (2.9) | <0.001 |
| FVC (mL) | 2,245 (1,050) | 2,416 (1,064) | 2,136 (1,028) | 0.004 |
| FVC (%) | 67.8 (17.5) | 70.6 (16.9) | 66.1 (17.7) | 0.006 |
| FEV1 (mL) | 1,141 (624) | 1,282 (662) | 1,052 (583) | <0.001 |
| FEV1 (%) | 47.1 (17.5) | 50.7 (17.3) | 45.4 (17.6) | 0.001 |
| FEV1/FVC (%) | 51.2 (11.6) | 52.9 (12.0) | 50.8 (12.4) | 0.069 |
| CAT (units) | 11.0 (8.0–16.0) | 10.0 (7.0–15.0) | 11.0 (9.0–15.0) | 0.028 |
| CCQ (units) | 2.0 (1.3–2.8) | 1.9 (1.1–2.7) | 2.2 (1.5–2.8) | 0.013 |
| COPDSS (units) | 11.0 (8.0–15.0) | 10.9 (8.0–14.0) | 12.3 (9.0–16.0) | 0.001 |
| AQ20 (units) | 8.0 (5.0–11.0) | 7.5 (4.0–10.0) | 8.3 (5.0–11.0) | 0.048 |
Notes: Values are expressed as mean (SD) and frequency (%). CAT, CCQ, COPDSS, and AQ20 questionnaires are expressed as median (interquartile range). P-value compares patients who suffered combined event with those who did not during the study follow-up.
Abbreviations: AQ20, Airways Questionnaire; CAT, COPD Assessment Test; CCQ, Clinical COPD Questionnaire; COPDSS, COPD Severity Score; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; SD, standard deviation.