Baseline characteristics of study population, the derivation cohort stratified around hospital admission
| Baseline features | <70 years | ≥70 years | ||||
| Discharged, n=6714 | Admitted, n=2014 | p Value | Discharged, n=1181 | Admitted, n=898 | p Value | |
| Age, median, IQR | 41.9 (26.8–55.6) | 52.4 (40.0–62.0) | <0.001 | 78.1 (73.7–83.4) | 78.1 (74.2–83.7) | 0.280 |
| Male, n (%) | 3625 (54.0) | 1137 (56.5) | 0.052 | 529 (44.8) | 466 (51.9) | 0.001 |
| Triage category, n (%) | <0.001 | <0.001 | ||||
| <10 min | 1066 (15.9) | 855 (42.5) | 270 (22.9) | 387 (43.1) | ||
| <1 hour | 2609 (38.9) | 958 (47.6) | 530 (44.9) | 413 (46.0) | ||
| <2 hours | 3007 (44.8) | 198 (9.8) | 374 (31.7) | 98 (10.9) | ||
| <4 hours | 32 (0.5) | 3 (0.1) | 7 (0.6) | 0 (0) | ||
| Arrival mode, n (%) | <0.001 | <0.001 | ||||
| Self-referral | 3648 (54.3) | 610 (30.3) | 303 (25.7) | 164 (18.3) | ||
| Ambulance/other institution | 782 (11.6) | 534 (26.5) | 287 (24.3) | 309 (34.4) | ||
| Referred by general practitioner/specialist | 2284 (34.0) | 870 (43.2) | 591 (50.0) | 425 (47.3) | ||
| Type of specialist | <0.001 | <0.001 | ||||
| Medicine | 2430 (36.2) | 1379 (68.5) | 605 (51.2) | 646 (71.9) | ||
| Surgery | 4284 (63.8) | 635 (31.5) | 576 (48.8) | 252 (28.1) | ||
| Revisit to the ED, n (%) | <0.001 | |||||
| Visit <30 days | 595 (8.9) | 327 (16.2) | 118 (10.0) | 129 (14.4) | 0.002 | |
| Chief complaint1 | <0.001 | <0.001 | ||||
| Minor trauma | 3370 (50.6) | 286 (14.3) | 456 (39.0) | 165 (18.4) | ||
| Major trauma | 103 (1.5) | 80 (4.0) | 11 (0.9) | 21 (2.3) | ||
| Chest pain | 764 (11.5) | 216 (10.8) | 215 (18.4) | 87 (9.7) | ||
| Dyspnoea | 238 (3.6) | 188 (9.4) | 93 (7.9) | 128 (14.3) | ||
| Syncope | 141 (2.1) | 78 (3.9) | 64 (5.5) | 54 (6.0) | ||
| Psychiatric complaints | 127 (1.9) | 92 (4.6) | 13 (1.1) | 21 (2.3) | ||
| Malaise | 526 (7.9) | 506 (25.3) | 136 (11.6) | 241 (26.9) | ||
| Abdominal pain | 592 (8.9) | 343 (17.1) | 81 (6.9) | 102 (11.4) | ||
| Other | 804 (12.1) | 214 (10.7) | 101 (8.6) | 76 (8.5) | ||
| Vital signs | ||||||
| Systolic BP, mm Hg2 | 138 (20) | 135 (23) | <0.001 | 148 (27) | 142 (27) | <0.001 |
| O2 saturation, %3 median, IQR | 99 (98–100) | 99 (97–100) | <0.001 | 98 (96–100) | 98 (95–99) | <0.001 |
| Temperature, °C4 | 36.9 (0.7) | 37.2 (1.1) | <0.001 | 36.8 (0.6) | 37.1 (1.2) | <0.001 |
| Respiratory rate, per minute5 | 16.9 (3.9) | 18.6 (5.4) | <0.001 | 17.5 (4.3) | 19.7 (6.1) | <0.001 |
| Heart rate, per minute6 | 83 (19) | 91 (22) | <0.001 | 82 (21) | 86 (20.7) | 0.002 |
| Performed test, n (%) | <0.001 | <0.001 | ||||
| Phlebotomised blood sample | 2868 (42.7) | 1846 (91.7) | 747 (63.3) | 859 (95.7) | ||
-Values are mean, SD unless noted otherwise.
-Vital parameters measured are O2, oxygen saturation, measured in percentage oxygenated haemoglobin; systolic BP, measured in millimetres of mercury; temperature measured in °C; Heart rate and respiratory rate, measured as times per minute.
Number of measured values per age group: <70 years: 1: n=8668; 2: n=5006; 3: n=5000; 4: n=4795; 5: n=2895; 6: n=5178. ≥70 years: 1: n=2065; 2: n=1589; 3: n=1582; 4: n=1434; 5: n=1154; 6: n=1614.
-p Values are measured by t-test for scale values and Χ2 for categorical values, and Mann-Whitney U test for non-parametric variables.