Table 1 Characteristics of the study cohort
Variable | Total cohort (n = 6878) | Survivors (n = 5954) | Non-survivors (n = 924, 13.4 %) | p valuea |
|---|---|---|---|---|
Age, years (IQR) | 54.4 (38–69) | 53.2 (36–67) | 62.9 (48–75) | 0.001 |
Male, no. (%) | 4504 (66) | 3930 (66) | 574 (62) | 0.023 |
ICU admission source, no. (%) | 0.001 | |||
- Operating theatre | 3166 (46) | 2919 (49) | 247 (27) | |
- Emergency department | 1813 (26) | 1508 (25) | 305 (33) | |
- Ward | 574 (8) | 422 (7) | 152 (16) | |
- CCU/HDU | 286 (4) | 213 (4) | 73 (8) | |
- Other hospital | 930 (14) | 806 (14) | 124 (13) | |
- Other hospital ICU | 55 (1) | 42 (1) | 13 (1.4) | |
Elective surgery, no. (%) | 1881 (27) | 1798 (30) | 83 (9) | 0.001 |
Ward stay before ICU, days (IQR) | 5 (2–10) | 5 (2–10) | 4 (2–13) | 0.958 |
Mechanical ventilation on adm (%) | 5412 (79) | 4677 (79) | 735 (80) | 0.383 |
Acute renal failure on adm, no. (%)b | 392 (6) | 185 (3) | 207 (22) | 0.001 |
Worst 24-h APACHE II score (IQR) | 17.0 (12–22) | 16 (12–21) | 27 (21–32) | 0.001 |
SAPS III score (IQR) | 43 (34–54) | 41 (33–50) | 60 (51–68) | 0.001 |
SAPS III predicted risk, % (IQR) | 7.9 (3–22) | 6.3 (2–16) | 32.8 (17–49) | 0.001 |
MPM0 III predicted risk, % (IQR) | 15.7 (8–31) | 13.9 (7–26) | 41.5 (22–68) | 0.001 |
ICU stay, days (IQR) | 3 (2–6) | 3 (2–6) | 4 (2–7) | 0.001 |
Hospital stay, days (IQR) | 13 (7–25) | 14 (8–26) | 6 (3–17) | 0.001 |
Chronic medical conditions (%)b | ||||
- Respiratory | 314 (5) | 264 (4) | 50 (5) | 0.203 |
- Cardiovascular | 679 (10) | 579 (10) | 100 (11) | 0.313 |
- Liver | 167 (2) | 127 (2) | 40 (4) | 0.001 |
- Renal | 323 (5) | 244 (4) | 79 (9) | 0.001 |
- Immune disease | 69 (1) | 51 (0.9) | 18 (2) | 0.004 |
- Immune treatment | 252 (4) | 185 (3) | 67 (7) | 0.001 |
- Metastatic cancer | 93 (1) | 71 (1) | 27 (2) | 0.008 |
- Lymphoma | 39 (0.6) | 25 (0.4) | 14 (2) | 0.001 |
- Leukaemia/myeloma | 83 (1) | 53 (0.9) | 30 (3) | 0.001 |
- AIDS | 7 (0.1) | 3 (0.05) | 4 (0.4) | 0.008 |
Major admission diagnoses, no. (%) | ||||
Cardiac or respiratory arrest | 345 (5) | 182 (3) | 163 (18) | 0.001 |
Pneumonia | 265 (4) | 23 (4) | 42 (5) | 0.233 |
Septic shock | 36 (6) | 324 (5) | 112 (12) | 0.001 |
Multiple trauma | 491 (7) | 455 (8) | 36 (4) | 0.001 |
Isolated head trauma | 620 (9) | 526 (9) | 94 (10) | 0.195 |
Intracranial haemorrhage | 235 (3) | 154 (3) | 81 (9) | 0.001 |
Drug overdoses | 449 (7) | 441 (7) | 8 (0.9) | 0.001 |
Congestive heart failure, ischaemic heart disease or cardiogenic shock | 179 (3) | 129 (2) | 50 (5) | 0.001 |
Peripheral vascular disease or aortic aneurysm | 205 (3) | 184 (3) | 21 (2) | 0.211 |
GI obstruction or perforation | 161 (2) | 134 (2) | 27 (3) | 0.200 |
Aspiration pneumonia | 76 (1) | 68 (1) | 8 (0.9) | 0.611 |
Obstructive airway disease | 136 (2) | 127 (2) | 9 (1) | 0.015 |
Heart valve surgery | 516 (8) | 503 (8) | 13 (1) | 0.001 |
Coronary artery bypass graft surgery | 982 (14) | 958 (16) | 24 (3) | 0.001 |
Acute lung injury or ARDS | 27 (0.4) | 22 (0.4) | 5 (0.5) | 0.398 |
Gastrointestinal bleeding | 125 (2) | 106 (2) | 19 (2) | 0.511 |
Pulmonary embolism | 22 (0.3) | 16 (0.3) | 6 (0.6) | 0.106 |