Definitions of selected general hospital adverse events for risk prediction
| Health adverse event | Definition | Observation window (days)* |
| Secondary admission to an ICU | Admission to an ICU during hospitalisation other than on the day of hospital admission or the same day as surgery. | 1 |
| Prolonged hospital stay | Hospitalisations with a length of stay (in days) above the 90th percentile for the general population are defined as prolonged. | 2 |
| 30-day readmission | Re-hospitalisation within 30 days of discharge. | Entire stay |
| 7-day readmission | Re-hospitalisation within 7 days of discharge. | Entire stay |
| Nosocomial bacterial infection | An associated diagnosis of significant bacterial infection at discharge, indicating infection acquired during the hospitalisation in patients admitted for other reasons. | 2 |
| Hospital-acquired venous thromboembolic disease | Hospital-acquired venous thromboembolic disease includes: pulmonary embolism and deep vein thrombosis (DVT, that can be either DVT-L=lower limb or DVT-U=upper limb). | 1 |
| In-hospital death | Adult patients who died between the 2nd and the 30th night after admission. | 1 |
| High-risk patients (in-hospital death, long length of stay and ICU secondary admission) | Adult patients who died (as defined above), were hospitalised over a long period (over 17 days) or had secondary ICU admission (as defined above). | 2 |
*A ‘1-day observation window’ is information collected from at least one complete day of stay, including overnight. A ‘2-day observational window’ is information collected from at least two complete days of stay, including two nights.
ICU, intensive care unit.