Modified Early Warning Score scores in the emergency department: Factors associated with changing scores to evaluate clinical improvement or deterioration.

Background: In the acute care chain, a heterogeneous group of patients seeks medical attention, of whom a small proportion become critically ill. Prediction models, such as the Modified Early Warning Score (MEWS), may assist in the identification of these patients and thereby prevent serious adverse events. The delta score within the emergency room (emergency department [ED]) is associated with outcome. However, it is unknown which factors contribute to these changes in MEWS scores. Methods: This is a retrospective cohort study at the Amsterdam University Medical Center, which included adult patients presented to the ED by ambulance from March 2022 to October 2022. We collected MEWS at ambulance arrival and 3 h after ED admission, as well as information about diagnostic tests, therapy, and interventions. Our primary outcome was the association of patients' characteristics and acute care actions (diagnostics, therapy, and interventions) with changes in the MEWS score. Results: A total of 261 patients were included. A higher MEWS at presentation with subsequent improvement was related to better outcomes and they received more therapeutic interventions and the administration of therapy, although these results may have been biased by the need for oxygen supply in respiratory unstable patients. In comparison with patients with normal and stable MEWS scores, they received overall less therapy. Conclusion: MEWS could be used to predict short-term critical illness in patients presenting to the ED. Further research is needed to evaluate the association of the acute care chains' performance and changes in MEWS scores.