Diagnostic accuracy of early warning system scores in the prehospital setting

The utilisation of pre-hospital early warning scores in ambulance services is widely endorsed to promptly identify patients at risk of clinical deterioration. Early warning scores enable clinicians to estimate risk based on clinical observations and vital signs, with higher scores indicating an elevated risk of adverse outcomes. Local healthcare systems establish threshold values for these scores to guide clinical decision-making, triage, and response, necessitating a careful balance between identifying critically unwell patients and managing the challenge of prioritisation. Given the limited evidence for optimal early warning scores in emergency department and pre-hospital care settings, a systematic review by Guan et al. (2022) was undertaken to assess the diagnostic accuracy of early warning scores for predicting in-hospital deterioration when applied in the emergency department or pre-hospital setting. This commentary aims to critically appraise the methods used within the review Guan et al (2022) and expand upon the findings in the context of clinical practice.