'Endless variation on a theme': a document analysis of international and UK major trauma triage tools.

Introduction: Triage tools are used within trauma networks to identify which injured patients should be bypassed and pre-alerted to major trauma centres. Despite the importance of treating the 'right patient in the right place at the right time', there has been no consensus on triage tool structure or content. This study aimed to identify, collate, review, summarise and recognise patterns across established major trauma triage tools.

Methods: UK and international triage tools used between 2012 and 2021 were identified through literature review and correspondence with trauma networks. A conceptual content analysis was then undertaken using an inductive codebook, comprising concepts of triage tool structure, intended population, inclusion criteria and included variables and thresholds. Thematic analysis was also performed to identify higher-level patterns within the data, with emerging patterns becoming categories for analysis. A narrative synthesis of findings was then undertaken.

Results: In total, 53 major trauma tools were identified, comprising 19 UK tools and 35 published international tools. Most triage tools (n = 42/53, 80%) were developed by expert opinion, were paper based and shared a common structure of multiple domains, with constituent triage predictors assessed in parallel. A minority of tools were statistically derived prediction models, operationalised either as simple scores (n = 10, 19%) or as an electronic application (n = 1, 1%). Overall, 173 distinct triage variables were used, with the median number of constituent triage variables per triage tool being 19 (range 3-31). Four distinct patterns of triage tools were identified during thematic analysis, which differed in terms of format, number of triage variables, thresholds, scope for clinical judgement and relative diagnostic accuracy.

Conclusion: Many diverse major trauma triage tools were identified, with no consensus in format, structure or content. Quantification of constituent variables and identification of distinct categories of triage tools may guide the design of future triage tools.