Table 2.
Demographic and clinical data for APACHE II sample
| Patient characteristic | Development | Validation |
| Cases (n) | 1863 | 932 |
| Age (mean ± SD) | 62.5 ± 16.1 | 61.8 ± 16.3 |
| Medical (%) | 65.5 | 66.0 |
| Surgical (%) | 34.5 | 34.0 |
| Direct admission (%) | 69.9 | 68.1 |
| Referral (%) | 30.1 | 31.9 |
| < 65 years (%) | 49.1 | 52.0 |
| ≥ 65 years (%) | 50.9 | 48.0 |
| Cardiovascular (%) | 38.9 | 38.6 |
| Gastrointestinal (%) | 32.9 | 31.8 |
| DOS ICU (mean ± SD) | 3.95 ± 7.0 | 3.48 ± 5.4 |
| DOS hospital (mean ± SD) | 25.35 ± 22.4 | 25.26 ± 22.5 |
| Hospital mortality (%) | 18.5 | 17.2 |
| APACHE II prediction (%) | 17.3 | 16.6 |
| APACHE III prediction (%) | 14.7 | 14.7 |
There were no differences for the APACHE III sample (1772/889 cases). Direct admission is defined as admission from emergency room, operating theatre, or recovery room; and transferral is defined as admission from other hospital, other ICU, or floor. DOS, duration of stay.