Table 1 Baseline characteristics of the study participants: entire cohort
| Severe COPD exacerbation | p | |||
|---|---|---|---|---|
|
All N = 12,554 (100.0) |
No N = 10,999 (87.6) |
Yes N = 1555 (12.4) | ||
| Severe COPD exacerbations, N (range) | 1.49 ± 1.09 (1–11) | |||
| General characteristics | ||||
| Male | 6880 (54.8) | 5867 (53.3) | 1013 (65.1) | < 0.001 |
| Age at the beginning of the study, yrs | 66.74 ± 11.26 | 66.13 ± 11.20 | 71.05 ± 10.76 | < 0.001 |
| Health insurance type | ||||
| Medical aids | 1681 (13.4) | 1279 (11.6) | 402 (25.9) | < 0.001 |
| Health insurance | 10,873 (86.6) | 9720 (88.4) | 1153 (74.2) | |
| Household income | ||||
| 1st quintile | 1723 (13.7) | 1547 (14.1) | 176 (11.3) | < 0.001 |
| 2nd quintile | 1483 (11.8) | 1318 (12.0) | 165 (10.6) | |
| 3rd quintile | 1816 (14.5) | 1633 (14.9) | 183 (11.8) | |
| 4th quintile | 2471 (19.7) | 2215 (20.1) | 256 (16.) | |
| 5th quintile | 3265 (26.0) | 2910 (26.5) | 355 (22.8) | |
| Missing | 115 (0.9) | 97 (0.9) | 18 (1.2) | |
| Comorbidities | ||||
| Comorbid diseases, N (range) |
2.56 ± 1.88 (0–12) |
2.52 ± 1.86 (0–12) |
2.88 ± 2.01 (0–10) | < 0.001 |
| 0 | 1435 (11.4) | 1307 (11.9) | 128 (8.2) | < 0.001 |
| 1 or 2 | 5510 (43.9) | 4866 (44.2) | 644 (41.4) | |
| 3 or 4 | 3569 (28.4) | 3101 (28.2) | 468 (30.1) | |
| ≥ 5 | 2040 (16.3) | 1725 (15.7) | 315 (20.3) | |
| Cardiovascular comorbidity | 6927 (55.2) | 6028 (54.8) | 899 (57.8) | 0.026 |
| Hypertension | 5835 (46.5) | 5098 (46.4) | 737 (47.4) | 0.439 |
| Ischemic heart disease | 1978 (15.8) | 1695 (15.4) | 283 (18.2) | 0.005 |
| Cardiac arrhythmia | 888 (7.1) | 749 (6.8) | 139 (8.9) | 0.002 |
| Heart failure | 943 (7.5) | 763 (6.9) | 180 (11.6) | < 0.001 |
| Cerebrovascular disease | 1273 (10.1) | 1057 (9.6) | 216 (13.9) | < 0.001 |
| Peripheral vascular disease | 1006 (8.0) | 889 (8.1) | 117 (7.5) | 0.448 |
| Respiratory comorbidity other than COPD | 6917 (55.1) | 5905 (53.7) | 1012 (65.1) | < 0.001 |
| Asthma | 6667 (53.1) | 5686 (51.7) | 981 (63.1) | < 0.001 |
| Bronchiectasis | 738 (5.9) | 611 (5.6) | 127 (8.2) | < 0.001 |
| Metabolic comorbidity | 5840 (46.5) | 5071 (46.1) | 769 (49.5) | 0.013 |
| Dyslipidaemia | 3352 (26.7) | 2950 (26.8) | 402 (25.9) | 0.419 |
| Diabetes mellitus | 3078 (24.5) | 2643 (24.0) | 435 (28.0) | 0.001 |
| Osteoporosis | 1914 (15.3) | 1638 (14.9) | 276 (17.8) | 0.003 |
| Chronic kidney disease | 147 (1.2) | 124 (1.1) | 23 (1.5) | 0.228 |
| GI comorbidity | 3625 (28.9) | 3196 (29.1) | 429 (27.6) | 0.232 |
| Gastroesophageal reflux disease | 3213 (25.6) | 2827 (25.7) | 386 (24.8) | 0.457 |
| Chronic liver diseases | 657 (5.2) | 578 (5.3) | 79 (5.1) | 0.772 |
| Malignancy comorbidity | 478 (3.8) | 381 (3.5) | 97 (6.2) | < 0.001 |
| Lung cancer | 204 (1.6) | 155 (1.4) | 49 (3.2) | < 0.001 |
| Stomach cancer | 51 (0.4) | 39 (0.4) | 12 (0.8) | 0.016 |
| Colorectal cancer | 47 (0.4) | 44 (0.4) | 3 (0.2) | 0.211 |
| Liver cancer | 45 (0.4) | 37 (0.3) | 8 (0.5) | 0.271 |
| Thyroid cancer | 41 (0.3) | 37 (0.3) | 4 (0.3) | 0.609 |