Early Warning Scores in Emergency Department Patients Aged 80 Years or Older

IMPORTANCE Early warning scores (EWSs) are widely used tools to support triage and risk stratification in the emergency department (ED). However, data on their performance in identifying clinical deterioration among acutely ill adults aged 80 years or older are scarce. OBJECTIVE To evaluate and compare the performance of 5 EWSs for predicting short-term clinical deterioration in ED patients aged 80 years or older. DESIGN, SETTING, AND PARTICIPANTS This retrospective prognostic study included all consecutive nontrauma ED visits by patients aged 80 years or older between January 2015 and December 2024 at a large urban teaching hospital in Rome, Italy. EXPOSURES Physiologic parameters recorded at ED admission were used to calculate 5 EWSs: National EarlyWarning Score (NEWS), National EarlyWarning Score 2 (NEWS2), Modified Early Warning Score (MEWS), Rapid Emergency Medicine Score (REMS), and International EarlyWarning Score (IEWS). MAIN OUTCOMES AND MEASURES The primary outcome was clinical deterioration, defined as death or intensive care unit (ICU) admission within 24 hours of ED arrival. Discrimination was assessed by area under the receiver operating characteristic curve (AUROC), calibration by the Brier score, and age-related performance by spline regression. Comparative contributions of variables were analyzed using Shapley additive explanations (SHAP) values. RESULTS Among 50 645 patients (median age, 85 years [IQR, 82-88 years]; 54.6þmales), 1233 (2.4%) experienced clinical deterioration. All EWSs demonstrated fair discrimination (AUROC range, 0.747 [IQR, 0.731-0.763] forMEWS to 0.782 [IQR, 0.767-0.798] forNEWS). WhereasNEWS achieved the highest AUROC, REMS had the best calibration (Brier score, 0.0220; 95%CI, 0.0208-0.0232). Discriminatory performance declined with increasing age beyond 90 years except for REMS, whose predictive accuracy improved among patients older than 94 years. For patients aged 87 years or older vs 80 to 86 years, oxygen supplementation (SHAP difference, 0.59), systolic blood pressure (SHAP difference, 0.32), and Glasgow Coma Scale score (SHAP difference, 0.40) were the strongest predictors of clinical deterioration. CONCLUSIONS AND RELEVANCE In this prognostic study of EWSs conducted among ED patients aged 80 years or older, all scores provided acceptable short-term prognostic accuracy. REMS demonstrated the most consistent performance in patients aged 94 years or older, supporting its use for targeted risk stratification in this population.