National Early Warning Score in Predicting Adverse Outcomes for Patients Admitted to Emergency Department; a Prognostic Accuracy Study.

Introduction: Overcrowding in emergency departments (ED) is a global concern, emphasizing the need for effective resource allocation. Triage plays a crucial role in prioritizing patients based on medical needs. This study aimed to evaluate the accuracy of National Early Warning Score (NEWS) in predicting the ED patients' outcomes. Methods: A cross-sectional study was conducted in two tertiary hospitals in Tehran, Iran, from June to July 2023. Adult patients presenting to ED were included. Data for calculating the NEWs and emergency severity index (ESI), as well as outcomes were recorded by trained nurses, and then the accuracy of each score in predicting the outcomes was evaluated. Results: A total of 2,085 patients were analyzed. The majority were male (57%) with a mean age of 54.4 years. The primary outcome, cardiopulmonary resuscitation (CPR) within 24 hours of admission, occurred in 1.9% of patients, while the need for intensive care unit (ICU) care and/or mechanical ventilation happened in 3.4%, and CPR or need for ICU care and/or mechanical ventilation was observed in 4.3% of studied cases. Each one-point increase in NEWS was associated with a 52% higher likelihood of CPR (95% confidence interval (CI): 1.41 to 1.65, p<0.001). Receiver operating characteristic curve analyses for the NEWS yielded the optimum cut-off value to be 6 for all three outcomes, with an overall area under the curve (AUC) of 0.856 (95% CI: 0.840 to 0.871), 0.834 (95% CI: 0.817 to 0.850), and 0.854 (95% CI: 0.838 to 0.869) for the primary, secondary, and tertiary outcomes, respectively. Conclusion: NEWS ≥ 6 was associated with a higher incidence of adverse outcomes, including ICU admission and need for CPR. The good predictive validity of NEWS highlights its value in identifying patients at higher risk of adverse outcomes.