Early Warning Scores for COVID-19 Outcomes: Modified Early Warning Score and Rapid Emergency Medicine Score Performance in Mortality and Hospital Readmission Risk Stratification.

Abstract

Background: The COVID-19 pandemic highlighted the need for rapid and reliable triage tools to predict patient outcomes and support resource allocation. This study aimed to compare the predictive performance of Modified Early Warning Score (MEWS) and Rapid Emergency Medicine Score (REMS) for predicting mortality and hospitalization among COVID-19 patients.

Materials and methods: This prospective cohort study included 900 outpatients and 280 inpatients with COVID-19 who presented to 22 Bahman Hospital in Neyshabur, Iran, between 2022 and 2024. Physiological parameters for both MEWS and REMS were recorded at admission and monitored for 30 days. The receiver operating characteristic curves were used to assess the prognostic accuracy of MEWS and REMS for mortality and hospitalization.

Results: At 48 hours before death, MEWS showed slightly better discrimination than REMS (AUC = 74.00, 95% CI: 68.80, 79.20 vs. 73.20, 95% CI: 67.50, 78.90; both p < 0.001). REMS exhibited greater sensitivity (75.50 vs. 38.00), while MEWS showed higher specificity (84.60 vs. 75.80). At 24 hours before death, REMS marginally outperformed MEWS (AUC = 62.80, 95% CI: 55.50, 70.10 vs. 62.30, 95% CI: 54.90, 69.70; p < 0.001 and < 0.001 respectively), with higher sensitivity (48.90 vs. 42.80) and slightly lower specificity (75.00 vs. 83.60).

Conclusions: REMS demonstrated better prognostic accuracy 24 hours before death, likely reflecting its inclusion of age and neurological status. MEWS showed stronger performance 48 hours before death and in predicting hospitalization.