Table 1.
Patient characteristics and outcome.
| Characteristic | Entire cohort | Development cohort | Validation cohort |
|---|---|---|---|
| Number of admissions | 835,946 | 417,972 | 417,974 |
| Age (years), mean (SD) | 61.5 (17.8) | 61.5 (17.8) | 61.5 (17.8) |
| Gender, n (%) | |||
| Female | 375,998 (45.0) | 187,459 (44.8) | 188,539 (45.1) |
| Male | 459,948 (55.0) | 230,513 (55.2) | 229,435 (54.9) |
| Presence of any severe comorbidity, n (%) | 146,809 (17.7) | 73,620 (17.7) | 73,189 (17.6) |
| Main diagnostic category, n (%) | |||
| Gastrointestinal | 232,857 (27.9) | 116,485 (27.9) | 116,372 (27.8) |
| Respiratory | 171,675 (20.5) | 85,714 (20.5) | 85,961 (20.6) |
| Cardiovascular | 127,103 (15.2) | 63,741 (15.3) | 63,362 (15.2) |
| Neurological | 91,809 (11.0) | 45,818 (11.0) | 45,991 (11.0) |
| Genitourinary | 86,671 (10.4) | 43,313 (10.4) | 43,358 (10.4) |
| Haematological | 9419 (1.1) | 4728 (1.1) | 4691 (1.1) |
| Endocrine | 66,106 (7.9) | 33,151 (7.9) | 32,955 (7.9) |
| Musculoskeletal | 41,244 (4.9) | 20,457 (4.9) | 20,787 (5.0) |
| Dermatological | 9032 (1.1) | 4549 (1.1) | 4483 (1.1) |
| APACHE II Acute Physiology Score, mean (SD) | 11.4 (6.1) | 11.4 (6.1) | 11.4 (6.1) |
| APACHE II Score, mean (SD) | 15.6 (7.0) | 15.6 (7.0) | 15.6 (7.0) |
| ICNARC Physiology Score, mean (SD) | 16.8 (9.3) | 16.8 (9.4) | 16.8 (9.3) |
| ICNARCH-2015 predicted risk of acute hospital mortality (%) | |||
| Mean (SD) | 20.7 (26.2) | 20.7 (26.3) | 20.7 (26.2) |
| Median (IQR) | 8.1 (2.1, 29.9) | 8.1 (2.1, 29.9) | 8.1 (2.1, 29.9) |
| ICU LOS (days) | |||
| Mean (SD) | 4.5 (7.6) | 4.4 (7.6) | 4.5 (7.7) |
| Median (IQR) | 2.1 (1.0, 4.8) | 2.1 (1.0, 4.8) | 2.1 (1.0, 4.8) |
| Total acute hospital LOS (days) | |||
| Mean (SD) | 20.4 (29.3) | 20.3 (29.0) | 20.5 (29.6) |
| Median (IQR) | 11 (6, 24) | 11 (5, 24) | 11 (6, 24) |
| Acute hospital outcome, n (%) | |||
| Alive | 656,020 (78.5) | 328,100 (78.5) | 327,920 (78.5) |
| Dead | 179,926 (21.5) | 89,872 (21.5) | 90,054 (21.5) |
APACHE: acute physiology and chronic health evaluation; LOS: length of stay; ICNARC: intensive care national audit & research centre; ICU: intensive care unit; IQR: interquartile range; SD: standard deviation.