Defining and Evaluating the Impact of Bleeding Severity on Time to Endoscopy and Mortality Risk: A Prospective Multicenter Cohort Study

<b>Background:</b> Upper gastrointestinal bleeding severity (BleSev) is commonly defined by evaluating different factors that are frequently interdependent on each other, expressing the same underlying cause. <b>Aim:</b> This study aimed to define the severity of a bleeding event and verify its impact on death risk and the time to endoscopy. <b>Methods:</b> We analyzed 12 factors (demographic, hemodynamic, biochemical, and clinical) that could be associated with BleSev. We identified the independent weight of each factor in predicting a composite endpoint (need for surgery, interventional radiology, and death) and the effect of the interactions between time to endoscopy and BleSev on death risk. <b>Results:</b> Clinical data of 2.525 patients were included. Of the 12 factors, 5 were retained in the final model as follows: altered mental status, systolic blood pressure ≤ 100 mmHg, blood urea nitrogen level ≥ 130 mg/dL, hematemesis, and hemoglobin level ≤ 8 g/dL (AUC performance curve, 0.79). We identified the following three classes of BleSev: low (0-1 points, 2.4%), intermediate (3-4 points, 8.6%), and high (≥5 points, 21.1%). When no factors were present, the death risk was 1%; when all factors were present, the risk was 45.5%. Notably, the death risk increased with BleSev but was generally independent of time to endoscopy. However, in high-risk cases, early endoscopy (within 6-12 h) was associated with a reduced mortality rate. <b>Conclusions:</b> This study defines a risk model for BleSev and highlights the need for targeted endoscopic timing strategies based on BleSev for optimizing survival rates. Patients in the highest risk category may benefit from more urgent endoscopic interventions.