In-hospital mortality in patients with lower gastrointestinal bleeding: development and validation of a prediction score

Abstract

Background Lower gastrointestinal bleeding (LGIB) is a common condition linked to increased morbidity, health- care costs, and mortality. Currently, no prospectively vali- dated prognostic model exists to predict mortality in patients with LGIB. Our aim was to develop and validate a risk score that could accurately predict in-hospital mortality of patients admitted for LGIB. Methods Patient data from a nationwide cohort study in 15 centers in Italy (2019–2020) were used to derive the risk score, the Acute Lower gastrointestinal Bleeding and In-hospital mortality (ALIBI) score; the model was then externally validated in a cohort of consecutive patients hos- pitalized for LGIB in 12 centers from six countries (Italy, Spain, France, Greece, Iran, and Brazil) from 2022 to 2024. The main outcome was in-hospital mortality; we also reported rebleeding rates and the in-hospital mortality rate stratified by risk score and timing of colonoscopy. Results Among 1198 patients in the derivation cohort, 105 (8.8%) re-bled and 41 (3.4%) died. Age, Charlson Co- morbidity Index, in-hospital onset, hemodynamic instabil- ity, and creatinine level were independent predictors of in- hospital mortality. The model demonstrated excellent dis- crimination (area under the receiver operating curve [AUR- OC] 0.81, 95%CI 0.75–0.87) and calibration. In the valida- tion cohort (n = 752 patients), the model's good discrimina- tion (AUROC 0.79, 95%CI 0.72–0.86) and calibration were confirmed. Patients were categorized as low (0–4 points; 1% mortality), intermediate (5–9 points; 4.6% mortality), or high risk (10–13 points; 19.1% mortality). Conclusion A new validated score effectively predicts in- hospital mortality in patients with LGIB, aiding in their risk stratification and management.