Prehospital national early warning score outperforms shock index in predicting mortality and resource utilisation in adult trauma: A systematic review.

In 30 seconds

This systematic review assessed prehospital Shock Index (SI) and National Early Warning Score (NEWS) for predicting mortality and resource use among adults with trauma. Twenty-two studies from diverse EMS systems were included, and heterogeneity required narrative synthesis. NEWS showed excellent discrimination for short-term mortality, with AUROC values of 0.87-0.96, and comparative studies found it outperformed SI across mortality endpoints. SI performance varied from poor to moderate (AUROC 0.48-0.79), although elevated SI was associated with higher mortality, transfusion, and critical care needs.

Key findings

• Prehospital NEWS had AUROC values of 0.87-0.96 for short-term mortality and reliably predicted transfusion and resource utilisation.
• SI mortality discrimination varied, with AUROC values of 0.48-0.79; elevated SI (>0.9) correlated with increased mortality, transfusion, and critical care needs.
• Comparative studies found NEWS outperformed SI across all mortality endpoints.
• SI accuracy was reduced in geriatric and isolated TBI populations; low SI (<0.4) showed potential prognostic value in severe TBI.

Why it matters

Early prehospital risk stratification can inform triage and preparation for likely resource needs. The review suggests NEWS may provide more consistent prognostic information than SI for adult trauma, while SI may still contribute to identifying patients needing urgent intervention. These findings highlight the potential value of evaluating broader physiological scoring systems alongside simple measures.

What to keep in mind

Substantial heterogeneity in study designs, populations, and outcome measures prevented quantitative synthesis. The review reports associations and prognostic accuracy, which do not establish that using NEWS improves patient outcomes.