Early Warning Scores in Emergency Medical Services as Prognostic Tools for Clinical Deterioration: A Literature Review

Abstract

Research objective: To compare the Modified Early Warning Score (MEWS), National Early Warning Score (NEWS/NEWS2), Rapid Emergency Medicine Score (REMS), and modified REMS (mREMS), and to evaluate the evidence supporting their use in prehospital care. Methodology: A literature review of publications from the preceding 20 years was conducted using PubMed, Scopus, and Google Scholar. Original peer-reviewed studies evaluating the selected scores in prehospital or ambulance-based populations formed the primary evidence set, while hospital studies, reviews, guidance, and technical resources provided context. Main findings: Ten primary studies directly evaluated at least one selected score in prehospital populations. NEWS/NEWS2 had the broadest evidence base. MEWS showed potentially useful discrimination for early deterioration, while REMS/mREMS provided additional prognostic stratification through patient age and a more detailed assessment of consciousness. No score was consistently superior across populations and outcomes. Application of the study: MEWS, NEWS/NEWS2, and REMS/mREMS may support risk stratification, repeated assessment, hospital pre-alert, communication, and escalation of care, but should complement rather than replace clinical judgement and locally validated pathways. Originality/Novelty of the study: The review directly compares the structure and prehospital prognostic evidence of three major score families and distinguishes ambulance-based findings from contextual hospital and implementation evidence.