Ann M, Rupert MP. A national early warning score for acutely ill patients. BMJ : British Medical Journal. 2012; 345

Aromataris E FR, Godfrey C, Holly C, Kahlil H, Tungpunkom P. Summarizing systematic reviews: methodological development, conduct and reporting of an Umbrella review approach. Int J Evid Based Healthc. 2015; 13:(3)132-134

Burgos-Esteban A, Gea-Caballero V, Marín-Maicas P, Santillán-García A, Cordón-Hurtado MV, Marqués-Sule E Effectiveness of Early Warning Scores for Early Severity Assessment in Outpatient Emergency Care: A Systematic Review. Front Public Health. 2022; 10

Eaton G. Addressing the challenges facing the paramedic profession in the United Kingdom. Br Med Bull. 2023;

Goodacre S, Sutton L, Thomas B Prehospital early warning scores for adults with suspected sepsis: retrospective diagnostic cohort study. Emerg Med J. 2023;

Guan G, Lee CMY, Begg S, Crombie A, Mnatzaganian G. The use of early warning system scores in prehospital and emergency department settings to predict clinical deterioration: A systematic review and meta-analysis. PLoS One. 2022; 17:(3)

Holland M, Kellett J. A systematic review of the discrimination and absolute mortality predicted by the National Early Warning Scores according to different cut-off values and prediction windows. Eur J Intern Med. 2022; 98:15-26

Lindskou TA, Ward LM, Søvsø MB, Mogensen ML, Christensen EF. Prehospital Early Warning Scores to Predict Mortality in Patients Using Ambulances. JAMA Netw Open. 2023; 6:(8)

Maciver M. Pre-hospital use of early warning scores to improve detection and outcomes of sepsis. Br J Community Nurs. 2021; 26:(3)122-129

Martín-Rodríguez F, López-Izquierdo R, Del Pozo Vegas C Can the prehospital National Early Warning Score 2 identify patients at risk of in-hospital early mortality? A prospective, multicenter cohort study. Heart Lung. 2020; 49:(5)585-591

NHS England. National Early Warning Score (NEWS). 2018. https// (accessed 22 November 2023)

Pirneskoski J, Kuisma M, Olkkola KT, Nurmi J. Prehospital National Early Warning Score predicts early mortality. Acta Anaesthesiol Scand. 2019; 63:(5)676-83

Diagnostic accuracy of early warning system scores in the prehospital setting

02 December 2023
Volume 15 · Issue 12


The use of prehospital 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 prehospital care settings, a systematic review was carried out by Guan et al (2022) to assess the diagnostic accuracy of early warning scores for predicting in-hospital deterioration when applied in the emergency department or prehospital setting. This commentary aims to critically appraise the methods used within the review by Guan et al (2022) and expand upon the findings in the context of clinical practice.

The use of prehospital early warning scores (EWS) in ambulance services settings is widely advocated, their aim being to identify patients at risk of clinical deterioration, early in their clinical course (Lindskou et al, 2023). Early warning scores allow the clinician to calculate a risk score for an individual patient (Ann and Rupert, 2012). This score is based upon their clinical observations and vital signs at the time of assessment, with the resulting score providing an indication as to their risk (Martín-Rodríguez et al, 2020). Higher scores are indicative of a higher risk of adverse outcome and deterioration, and serve to identify patients requiring an increased clinical response (Pirneskoski et al, 2019). Early warning scores can be applied across a range of conditions and may be generic in nature, although tools also exist for specific conditions such as sepsis (Maciver, 2021). Local healthcare systems set threshold values for the resultant score to guide clinical decision-making, triage, and response decisions (Goodacre et al, 2023). Care must be taken to maintain a balance, ensuring that the risks of overlooking potentially critically unwell patients are weighed against the challenge of prioritising too many patients and overwhelming healthcare systems (Goodacre et al, 2023).

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