Baseline characteristics of patients included for analysis
| Variable | Total (n =2226) | Critical outcome (−) (n=1792) | Critical outcome (+) (n=434) | P value |
| Age, years | 56.3±17.0 | 54.5±17.4 | 63.5±12.8 | <0.001 |
| Gender, male | 1529 (68.7) | 1205 (67.2) | 324 (74.7) | 0.003 |
| BMI, kg/m2 | 24.8±4.8 | 24.6±4.6 | 25.8±5.4 | <0.001 |
| Current smoker | 328 (15.7) | 268 (15.85) | 60 (15.0) | 0.703 |
| Smoking history | 982 (47.2) | 772 (45.8) | 210 (53.3) | 0.024 |
| Onset to hospitalisation, days | 7.03±4.50 | 6.53±4.15 | 8.77±5.18 | <0.001 |
| Comorbidities | ||||
| Hypertension | 741 (33.7) | 520 (29.0) | 221 (51.5) | <0.001 |
| Diabetes mellitus | 467 (21.2) | 313 (17.5) | 154 (35.7) | <0.001 |
| Cardiovascular disease | 214 (9.7) | 150 (8.4) | 64 (14.7) | <0.001 |
| Autoimmune disease | 90 (4.1) | 78 (4.4) | 12 (2.8) | 0.125 |
| COPD | 85 (3.9) | 54 (3.1) | 31 (7.2) | <0.001 |
| Asthma | 150 (6.9) | 124 (7.1) | 26 (6.1) | 0.459 |
| Hyperuricaemia | 231 (10.5) | 162 (9.2) | 69 (16.0) | <0.001 |
| Chronic liver disease | 99 (4.6) | 77 (4.5) | 22 (5.2) | 0.535 |
| Chronic kidney disease | 159 (7.5) | 91 (5.0) | 68 (15.7) | <0.001 |
| Treatment | ||||
| Antibiotics | 568 (25.7) | 289 (16.2) | 279 (65.2) | <0.001 |
| Favipiravir | 575 (26.0) | 439 (24.7) | 136 (31.7) | 0.003 |
| Remdesivir | 863 (39.2) | 564 (31.8) | 299 (69.5) | <0.001 |
| Tocilizumab | 269 (12.2) | 105 (5.9) | 164 (38.6) | <0.001 |
| Anticoagulant | 693 (31.4) | 326 (18.3) | 367 (85.8) | <0.001 |
| Systemic corticosteroid | 1168 (52.9) | 764 (42.9) | 404 (94.2) | <0.001 |
| Critical outcome | 434 (19.5) | 0 (0) | 434 (100.0) | <0.001 |
| High-flow oxygen therapy | 104 (4.7) | 0 (0) | 104 (24.0) | <0.001 |
| IPPV | 52 (2.4) | 0 (0) | 52 (12.2) | <0.001 |
| ECMO | 317 (14.3) | 0 (0) | 317 (73.0) | <0.001 |
| Mortality | 77 (3.5) | 0 (0) | 77 (17.7) | <0.001 |
Data are presented as mean±SD or n (%) of patients. Differences in variables with and without critical events were compared using unpaired t-test or χ2 test.
BMI, body mass index; COPD, chronic obstructive pulmonary disease; ECMO, extracorporeal membrane oxygenation; IPPV, invasive positive pressure ventilation.