Primary elements for formulating study purpose, search strategy, inclusion and exclusion criteria for the study according to the following PICOTS guidance
| Item | Definition |
| Population | Patients who were critically ill |
| Intervention | Any prediction model to predict the risk of acute kidney injury (AKI) in patients with critical illness, to distinguish critically ill patients with poor outcome (who will develop AKI), or to aid in clinical decision making in acute care, planning therapeutic intervention and monitoring treatment response |
| Comparator | Not applicable |
| Outcomes | AKI reported by prediction models |
| Timing | Predictive variables measured at any timepoint during the clinical course of the disease; no specific limitation applied in prediction horizon |
| Setting | Patients with critical illness who were admitted to hospital, treated in intensive care unit or emergency department |