Title: MATTS: MAjor trauma Triage Tool Study
Funder: Department of Health and Social Care

Abstract: AIM: To develop an accurate, acceptable and usable prehospital triage tool to identify patients with major trauma benefiting from MTC care, optimising over/under-triage. DESIGN: PHASE 1-Identification and development of triage tools, comprising: a) systematic review and document analysis of current tools; retrospective cohort study and focus groups with clinicians to identify predictors of major trauma. b) Decision analytical modelling evaluating benefit of MTC care, trade-offs between under/over-triage, and target triage sensitivity/specificity. c) Expert consensus process, informed by stages a) and b), to develop a new triage tool and define which patients should receive MTC care. PHASE 2-Prospective cohort study to validate and compare the diagnostic accuracy of paramedic judgement, existing, and consensus derived triage tools. -Setting: Major trauma networks within the West Midlands, Yorkshire, South West and London Ambulance Services and associated Air Ambulance Services. -Study population: Any patient attended by EMS following injury. Sub-group analyses of children and elderly patients >65 years. -Index tests: Paramedic judgement; existing and expert consensus derived major trauma triage tools -Reference standard: Patients with the potential to benefit from MTC care defined through independent expert consensus with clinicians and stakeholders, and PPI consultation. Secondary reference standards of ISS>15 and mortality/morbidity risk range defined from decision analytical modelling. -Outcomes: Under/over-triage rates, mortality. -Data collection: Linkage of triage tool variables, reference standard and outcomes using prospective EMS and augmented TARN data. -Sample size: The estimated prevalence of major trauma is 0.8% amongst EMS calls for injury. Collaborating ambulance services estimate 200,000 EMS calls for injury per 4 months. Assuming, based on ASCOT criteria, a triage tool requires under/over-triage rates of <5% and <30% respectively, this sample would provide 95% confidence intervals of ±1.0% and ±0.2% for under/over-triage rates. PHASE 3- Evaluation of system-level performance of optimal triage tool, comprising: a) investigation of under/over-triage after operational implementation in a major trauma network within each ambulance service; b) evaluation of acceptability and usability to patients, ambulance services, and other important stakeholders using mixed-methods; c) cost-effectiveness of alternative triage tools using decision analytical modelling. PROJECT TIMETABLE: 31m funded project. Phase 1: Permissions and set up, systematic review, retrospective cohort study, clinician focus groups, decision analytical modelling, and expert consensus process (10m); Phase 2: Prospective data collection, linkage and analysis (8m); Phase 3: triage tool implementation, mixed methods assessment of performance/acceptability/usability (7m); Close-out: cost-effectiveness modelling, analysis and write-up (6m). EXPERTISE: Highly experienced team with track record of successfully delivering challenging prehospital studies. Specialists in prehospital care, major trauma, health services research, data management/linkage, systematic reviews, statistics, health economics, and strong PPI input. Expert advisory group of methodologists, and key policy, ambulance service and clinical stakeholders.

Lay abstract: Serious injuries are a major health problem in England, responsible for 3,000 deaths and 8,000 disabilities each year. Treatment in specialist hospitals, called major trauma centres, can improve survival following such injuries. In order to benefit from this expert care, ambulance crews must first correctly identify suitable patients at the scene of injury and then transport them to a major trauma centre, bypassing any closer non-specialist hospital. The presence of serious injury is not always obvious and assessment can be difficult. Taking patients with minor injuries to the major trauma centre could waste time, money and resources; and could inconvenience patients and their families by taking them further from home. In contrast failing to recognise serious injury could result in less effective treatment. The term ‘triage’ means to sort patients in terms of priority. Paramedics currently use a ‘triage tool’ to help them to recognise whether a patient is seriously injured or not. The tool is a checklist of patient and injury features, for example the presence of low blood pressure, that indicate that care in a major trauma centre might be beneficial. Unfortunately, research has suggested that current tools are not very accurate, as they may miss patients with serious injury and often direct patients with more minor injuries to the major trauma centre unnecessarily. This study aims to develop a new and more accurate tool that will help get the right patient to the right place at the right time. We will carefully study existing triage tools used in England and world-wide. We will also use data already collected by ambulance services and the English national major trauma database (The Trauma Audit and Research Network, TARN) to investigate what factors are important for detecting serious injury at the scene of the incident. Additionally we will develop a computer ‘model’ that simulates the costs and outcomes of using different triage tools. Together, we will take this information to a group of experts and ask them to develop a new triage tool. We will then test the experts’ triage tool, together with other existing tools, to see how they perform. In order to do this we will link data that is routinely collected by the Yorkshire, West Midlands, South West and London Ambulance services, with information from TARN. It has been suggested that identifying major trauma in older people is particularly difficult, so we will also specifically focus on this age group. We will then take the best-performing tool and introduce it into practice in an area of each ambulance service, to see how it works in real-life. To find out about the experiences and views of patients and paramedics using the tool we will carry out interviews and focus groups. We will also consult with major trauma specialists, service managers and other stakeholders to assess the possible impact of the tool. We have talked to patients affected by serious injury, and a group of patients involved in research about emergency care, while developing these research ideas. Members of these groups have agreed to join an advisory panel to help guide any future study. We have included a lay person with personal experience of major trauma as part of our research team alongside specialists in emergency medicine and major trauma. We have also consulted national specialist groups and gained support from participating ambulance services.

Research activity codes: 7.3 MANAGEMENT AND DECISION MAKING
Health categories: INJURIES AND ACCIDENTS