Introduction Prognostic scores are widely used in the emergency department (ED) to stratify risk for critically ill patients. The Prince of Wales ED Score (PEDS) was derived specifically for patients in an ED resuscitation room to predict death or intensive care unit (ICU) admission. We aimed to validate and refine this score, in comparison with other scores including the National Early Warning Score (NEWS).

Methods This was a single-centre prospective study of adult resuscitation-room patients over 3 months.

Comparison of scores was made using receiver operating characteristic analysis. Physiological and blood test variables were compared according to the composite primary outcome: admission to ICU or death within 7 days of attendance. Multivariate logistic regression was used to derive a new prediction score, which was validated in comparison with NEWS using the historic dataset from which PEDS had been derived.

Results 234 patients were included; 37 were admitted to ICU or died within 7 days. PEDS performed adequately but was not superior to other scores. A simple pragmatic score, The Resuscitation Management score (THERM) was derived which outperformed NEWS in derivation and validation sets.

Conclusions PEDS is at least as good as other scores, including NEWS. However, it is unwieldy and relies on results not immediately accessible in the ED. THERM is a new score, derived and validated in an ED setting, using variables readily available, and simple to calculate and stratify. THERM outperforms NEWS and could be used in preference in critically ill ED patients.