Table 1 Demographic and clinical features of patients in the training and validation sets
| Â | Training set | Internal validation set | External validation set |
|---|---|---|---|
Number of patients, n | 610 | 1423 | 1596 |
Age, years | 59.5 (42.0–70.0) | 59.0 (44.0–71.0) | 60.0 (43.0–74.0) |
Male, n (%) | 331 (54.3) | 709 (49.8) | 832 (52.1) |
Body mass index, kg/m2 | 23.3 (21.2–26.0) | 23.4 (21.2–25.6) | 23.3 (20.9–25.7) |
Vaccination status, n (%) | |||
 Unvaccinated | 243 (39.8) | 616 (43.3) | 678 (42.5) |
 Partially vaccinated | 25 (4.1) | 42 (3.0) | 50 (3.1) |
 Fully vaccinated | 154 (25.2) | 335 (23.5) | 453 (28.4) |
 Boosted | 188 (30.8) | 430 (30.2) | 415 (26.0) |
Symptomatic, n (%) | 367 (60.2) | 878 (61.7) | 932 (58.4) |
Disease severity, n (%) | |||
 Asymptomatic/mild | 456 (74.8) | 1020 (71.7) | 1091 (68.4) |
 Moderate | 154 (25.2) | 403 (28.3) | 505 (31.6) |
Co-existing conditions, n (%) | |||
 Hypertension | 215 (35.2) | 476 (33.5) | 516 (32.3) |
 Cardio-cerebrovascular disease excluding hypertension | 122 (20.0) | 252 (17.7) | 261 (16.4) |
 Diabetes | 95 (15.6) | 201 (14.1) | 246 (15.4) |
 Chronic lung disease | 43 (7.0) | 110 (7.7) | 88 (5.5) |
 Chronic liver disease | 19 (3.1) | 46 (3.2) | 34 (2.1) |
 Chronic kidney disease | 30 (4.9) | 83 (5.8) | 95 (6.0) |
 Malignancy | 43 (7.0) | 108 (7.6) | 113 (7.1) |
 Immunol suppressed status | 17 (2.8) | 42 (3.0) | 27 (1.7) |
Charlson comorbidity index | 0.0 (0.0–2.0) | 0.0 (0.0–2.0) | 0.0 (0.0–1.0) |
Antiviral treatment, n (%) | 78 (12.8) | 169 (11.9) | 154 (9.6) |