The diagnostic accuracy of prehospital triage tools in identifying patients with traumatic brain injury: a systematic review

Introduction

Prehospital care providers are usually the first responders for patients with traumatic brain injury (TBI). Early identification of patients with TBI enables them to receive trauma centre care, which improves outcomes. Two recent systematic reviews concluded that prehospital triage tools for undifferentiated major trauma have low accuracy. However, neither review focused specifically on patients with suspected TBI. Therefore, we aimed to systematically review the existing evidence on the diagnostic performance of prehospital triage tools for patients with suspected TBI.

Methods

A comprehensive search of the current literature was conducted using Medline, EMBASE, CINAHL Plus and the Cochrane library (inception to 1st June 2021). We also searched Google Scholar, OpenGrey, pre-prints (MedRxiv) and dissertation databases. We included all studies published in English language evaluating the accuracy of prehospital triage tools for TBI. We assessed methodological quality and risk of bias using a modified Quality Assessment of Diagnostic Studies (QUADAS-2) tool. Two reviewers independently performed searches, screened titles and abstracts and undertook methodological quality assessments. Due to the heterogeneity in the population of interest and prehospital triage tools used, a narrative synthesis was undertaken.

Results

The initial search identified 1787 articles, of which 8 unique eligible studies met the inclusion criteria (5 retrospective, 2 prospective, 1 mixed). Overall, sensitivity of triage tools studied ranged from 19.8% to 87.9% for TBI identification. Specificity ranged from 41.4% to 94.4%. Two decision tools have been validated more than once: HITS-NS (2 studies, sensitivity 28.3–32.6%, specificity 89.1–94.4%) and the Field Triage Decision Scheme (4 studies, sensitivity 19.8–64.5%, specificity 77.4%-93.1%). Existing tools appear to systematically under-triage older patients.

Conclusion

Further efforts are needed to improve and optimise prehospital triage tools. Consideration of additional predictors (e.g., biomarkers, clinical decision aids and paramedic judgement) may be required to improve diagnostic accuracy.