Table 2. Patient characteristics in the development and validation cohorts.
| Variables | Development cohort (n = 7,373) |
Validation cohort (n = 821) |
||
| Age, years, median (IQR) | 74 | (58–82) | 70 | (50–81) |
| Age category, years | ||||
| ≤34 | 612 | (8.3) | 94 | (11.4) |
| 35–54 | 1,001 | (13.6) | 155 | (18.9) |
| 55–64 | 773 | (10.5) | 83 | (10.1) |
| 65–84 | 3,540 | (48.0) | 380 | (46.3) |
| ≥85 | 1,424 | (19.3) | 107 | (13.0) |
| Sex, male | 4,078 | (55.4) | 434 | (53.0) |
| Emergency medical service use | 5,836 | (81.3) | 509 | (66.3) |
| Admission | 3,658 | (49.6) | 399 | (48.6) |
| Diagnosis at emergency department [first letter of the ICD-10 codes] | ||||
| Infectious and parasitic diseases [A, B] | 241 | (3.3) | 13 | (1.6) |
| Neoplasms [C, D] | 209 | (2.8) | 13 | (1.6) |
| Endocrine, nutritional and metabolic diseases [E] | 266 | (3.6) | 36 | (4.4) |
| Mental and behavioral disorders [F] | 167 | (2.3) | 21 | (2.6) |
| Diseases of the nervous system [G] | 362 | (4.9) | 28 | (3.4) |
| Diseases of the eye, adnexa, ear and mastoid process [H] | 144 | (2.0) | 12 | (1.5) |
| Diseases of the circulatory system [I] | 1,472 | (20.0) | 115 | (14.0) |
| Diseases of the respiratory system [J] | 600 | (8.1) | 48 | (5.8) |
| Diseases of the digestive system [K] | 633 | (8.6) | 82 | (10.0) |
| Diseases of the skin and subcutaneous tissue [L] | 78 | (1.1) | 16 | (1.9) |
| Diseases of the musculoskeletal system and connective tissue [M] | 175 | (2.4) | 19 | (2.3) |
| Diseases of the genitourinary system [N] | 316 | (4.3) | 30 | (3.7) |
| Pregnancy, childbirth, puerperium and perinatal condition [O, P] | 5 | (0.1) | 3 | (0.4) |
| Symptoms, signs and abnormal clinical and laboratory findings [R] | 870 | (11.8) | 135 | (16.4) |
| Injury, poisoning and other consequences of external causes [S, T] | 1,231 | (16.7) | 135 | (16.4) |
| Others [X, Z, Q] | 18 | (0.2) | 2 | (0.2) |
| Missing data | 586 | (7.9) | 113 | (13.8) |
ICD-10, International Statistical Classification of Diseases, Tenth Revision; IQR, interquartile range.
Data are shown as n (%) unless otherwise specified.