The Brazilian risk assessment severity index score: a novel tool for predicting in-hospital mortality in emergency departments.

Abstract

BACKGROUND: Rapid identification of patients at risk of clinical deterioration (in-hospital mortality) in emergency settings is essential for timely and appropriate care. Existing prognostic scores, such as the Acute Physiology and Chronic Health Evaluation IV (APACHE IV), Simplified Acute Physiology Score 3 (SAPS 3), Sequential Organ Failure Assessment (SOFA), and National Early Warning Score 2 (NEWS 2), have limitations in emergency scenarios, particularly in resource-limited settings. We aimed to develop a simple and efficient tool tailored to the Brazilian healthcare system. METHODS: This retrospective, multicenter, cohort study analyzed data from 50,709 adult patients admitted to 12 hospitals in southern and southeastern Brazil between 2019 and 2020. The BRASIL score (Brazilian Risk Assessment Severity Index and Length of stay) was constructed using demographic and clinical variables available at admission. Logistic regression was used to determine the weight of each variable, and each variable was assigned a point value based on its β-coefficient and clinical relevance, with thresholds defined according to established medical cutoffs and statistical performance. The score's predictive accuracy was validated using the area under the receiver operating characteristic curve (AUC) with comparative analysis against NEWS 2. RESULTS: The BRASIL score, including age, sex, respiratory rate, heart rate, oxygen saturation, blood pressure, and body temperature, was derived through variables independently associated with in-hospital mortality in a multicenter cohort. The total score was stratified into three risk categories - low (0-3 points), moderate (4-7 points), and high (>7 points) - using observed inflection points in mortality distribution to optimize discrimination. This stratification demonstrated a stepwise increase in mortality rates across categories and the discriminatory performance, with an overall AUC of 0.743 (95% CI: 0.726-0.761). Compared to NEWS 2 (AUC 0.697, 95% CI: 0.683-0.711), the BRASIL score offered superior early risk identification, supporting timely clinical decision-making and resource allocation in the emergency setting. CONCLUSION: The BRASIL score is a novel tool for predicting in-hospital mortality in emergency departments. Its predictive performance and ease of use suggest that it has the potential to improve patient outcomes.