Abstract 2389: The Utility of the Modified Early Warning Score in Acute Stroke Patients

Abstract

Introduction. The Modified Early Warning Score (MEWS) is a tool for estimating risk of death or poor outcome in the Emergency Department (ED). It is a 0-14 point score based on initial physiological observations including heart rate, respiratory rate, systolic blood pressure, temperature and level of consciousness. In Acute medical patients, a score > 4 has been found to be associated with increased risk of death. The score is being widely adopted for use as a risk stratification tool for patients admitted through EDs and in Acute Medical Assessment Units and has been used in stroke patients but has not been validated for acute stroke. We applied the score to a population of acute stroke patients admitted through ED to determine its utility. Methods. Records on consecutive patients admitted through ED to an acute stroke service of an inner city university teaching hospital over 8 months were identified and MEWS calculated for each. Patients dying within 6 months or with a prolonged hospital stay (>42 days) were identified. Results. 132 subjects (Mean age 71, 59% male) were admitted to the service, 122 were admitted through ED. Median MEWS was 1 (range 0-4) and 18 (17%) died within 6 months. Subjects with a MEWS>2 were significantly more likely to die (10/91 vs 10/31 p=0.006 Chi square. O.R. 3.9 (1.4-10.5)) and those who survived more likely to have a prolonged length of stay (21/81 vs 11/21 p=0.02. Chi square. O.R 3.1 (1.2-8.5)). As a tool for identifying those with acute stroke risk of dying the MEWS performed only moderately well (PPV 0.5, NPV 0.68). Conclusion. As part of a screening test for stroke patients a MEWS>2 at ED admission is associated with worse outcome however it is neither sensitive or specific enough to be used in isolation as a means of triaging stroke patients into risk categories.