Table 1 Clinical characteristics and outcomes of patients admitted to ICUs during off-hours vs. office-hours
|  | Total (n = 28,200) | Off-hour admission (n = 20,403) | Office-hour admission (n = 7797) |
|---|---|---|---|
Age, median (IQR) | 71 (59–80) | 71 (59–80) | 71 (60–80) |
Female, n (%) | 10,902 (38.7) | 7986 (39.1) | 2916 (37.4) |
BMI, median (IQR) | 22.2 (19.6 to 25.0) | 22.2 (19.5 to 24.9) | 22.3 (19.6 to 25.2) |
APACHE II score, median (IQR) | 18 (13 to 24) | 17 (12 to 24) | 18 (13 to 25) |
Admission source, n (%) | |||
 Emergency departments | 13,588 (48.2) | 9751 (47.8) | 3837 (49.2) |
 Operating rooms | 7689 (27.3) | 6465 (31.7) | 1224 (15.7) |
 Non-ICU wards | 5739 (20.4) | 3611 (17.7) | 2128 (27.3) |
 Transfer from other hospitals | 617 (2.2) | 273 (1.3) | 344 (4.4) |
 Other | 567 (2.0) | 303 (1.5) | 264 (3.4) |
Type of hospital, n (%) | |||
 National/public hospitals | 9564 (33.9) | 6780 (33.2) | 2784 (35.7) |
 University hospitals | 11,694 (41.5) | 8453 (41.4) | 3241 (41.6) |
 Private hospitals | 6942 (24.6) | 5170 (25.3) | 1772 (22.7) |
Diagnosis at ICU admission, n (%) | |||
 Cardiovascular | 9839 (34.9) | 6848 (33.6) | 2991 (38.4) |
 Respiratory | 3531 (12.5) | 2315 (11.3) | 1216 (15.6) |
 Neurologic | 4105 (14.6) | 3079 (15.1) | 1026 (13.2) |
 Trauma | 1575 (5.6) | 1227 (6.0) | 348 (4.5) |
Emergent surgery, n (%) | 9517 (33.7) | 7647 (37.5) | 1870 (24.0) |
After cardiac resuscitation, n (%) | 1713 (6.1) | 1178 (5.8) | 535 (6.9) |
Chronic organ insufficiency, n (%) | |||
 Liver cirrhosis | 602 (2.1) | 420 (2.1) | 182 (2.3) |
 Renal dialysis | 1638 (5.8) | 1128 (5.5) | 510 (6.5) |
 Hematologic malignancy | 652 (2.3) | 416 (2.0) | 236 (3.0) |
 Solid tumor with metastasis | 916 (3.2) | 681 (3.3) | 235 (3.0) |
 Immunosuppression | 1828 (6.5) | 1,231 (6.0) | 597 (7.7) |
 One or more insufficiencies | 5526 (19.6) | 3819 (18.7) | 1707 (21.9) |
Invasive interventions in ICUs, n (%) | |||
 Mechanical ventilation | 13,234 (46.9) | 9539 (46.8) | 3695 (47.4) |
 CRRT | 1890 (6.7) | 1273 (6.2) | 617 (7.9) |
 IABP | 1131 (4.0) | 750 (3.7) | 381 (4.9) |
 ECMO | 556 (2.0) | 378 (1.9) | 178 (2.3) |
In-hospital mortality, n (%) | 5003 (17.7) | 3399 (16.7) | 1604 (20.6) |