External validation of the Dutch prediction model for prehospital triage of trauma patients in South West region of England, United Kingdom

Importance

This paper investigates the use of a major trauma prediction model in the UK setting. We demonstrate that application of this model could reduce the number of patients with major trauma being incorrectly sent to non-specialist hospitals. However, more research is needed to reduce over-triage and unnecessary transfer to Major Trauma Centres.

Objective

To externally validate the Dutch prediction model for identifying major trauma in a large unselected prehospital population of injured patients in England.

Design

External validation using a retrospective cohort of injured patients who ambulance crews transported to hospitals.

Setting

South West region of England.

Participants

All patients 16 years with a suspected injury and transported by ambulance in the year from February 1, 2017. Exclusion criteria: 1) Patients aged ≤15 years; 2) Non-ambulance attendance at hospital with injuries; 3) Death at the scene and; 4) Patients conveyed by helicopter. This study had a census sample of cases available to us over a one year period.

Interventions or exposures

Tested the accuracy of the prediction model in terms of discrimination, calibration, clinical usefulness, sensitivity and specificity and under- and over triage rates compared to usual triage practices in the South West region.

Main outcome measure

Major trauma defined as an Injury Severity Score>15.

Results

A total of 68799 adult patients were included in the external validation cohort. The median age of patients was 72 (i.q.r. 46-84); 55.5% were female; and 524 (0.8%) had an Injury Severity Score>15. The model achieved good discrimination with a C-Statistic 0.75 (95% CI, 0.73 – 0.78). The maximal specificity of 50% and sensitivity of 83% suggests the model could improve undertriage rates at the expense of increased overtriage rates compared with routine trauma triage methods used in the South West, England.

Conclusions and relevance

The Dutch prediction model for identifying major trauma could lower the undertriage rate to 17%, however it would increase the overtriage rate to 50% in this United Kingdom cohort. Further prospective research is needed to determine whether the model can be practically implemented by paramedics and is cost-effective.