Ambulance services in England have used different checklists to decide which injured patients should bypass the nearest hospital for a major trauma centre. The Major Trauma Triage Study (MATTS), led from the University of Sheffield and funded by the NIHR, built and tested one national tool. In live use it picked up just over half of major trauma cases while sending few others to specialist centres, but crews rarely recorded using it. If you make or support destination decisions for injured patients, these trade-offs are yours too.
Why this matters
England runs regional trauma networks. The most seriously injured patients should go to a major trauma centre (MTC), a hospital with specialist surgery, imaging and critical care on site around the clock. Others go to a trauma unit or local emergency department. The crew decides, often within minutes, using a triage tool. The study’s ethics summary states that serious injury accounts for around 3,000 deaths and 8,000 cases of disability in England each year.
The problem was consistency. The MATTS document review found 19 UK tools and 34 international ones. The same patient could be triaged differently depending on which service attended. The team’s systematic review of 15 studies also found that existing tools performed less well in older people.
Two terms matter. Under-triage means a patient with major trauma goes to a non-specialist hospital. Over-triage means a patient without major trauma goes to an MTC, using specialist capacity and often a longer journey. The American College of Surgeons targets are under-triage of 5% or less and over-triage of 35% or less. Sensitivity is the share of true major trauma cases a tool picks up; under-triage is what it misses. Specificity is the share of other injured patients it correctly leaves alone; over-triage is the remainder.
What the researchers did
MATTS was a three-phase mixed methods study funded by the NIHR Health Technology Assessment programme (award 17/16/04) and sponsored by the University of Sheffield. Yorkshire, West Midlands, South Western and London Ambulance Services took part. The full report appeared in Health Technology Assessment in May 2026.
Phase one developed the tool. A three-round Delphi survey narrowed 109 candidate variables to nine. The result was a three-step tool covering physiology, anatomical injury and clinical judgement, with variables assessed in parallel and remote decision support built in. Economic modelling favoured specificity, because major trauma is rare among injured patients and false positives carry real costs. Stakeholder work, with 81 questionnaires and six focus groups involving 62 people, found crews valued simplicity and room for judgement.
Phase two was a case-cohort validation from 1 November 2019 to 28 February 2020 across four trauma networks. This design samples all injured patients, adds every patient who met the reference standard, then weights the results. Ambulance records were matched to the Trauma Audit and Research Network (TARN) registry. The reference standard was a consensus definition of injury that would benefit from expedited MTC care, not an injury severity score alone. Twenty-two adult tools were tested, including three MATTS versions: specific, balanced and sensitive.
Phase three put the chosen tool into use. From 1 November 2021 to 15 May 2022 it ran across six trauma networks served by West Midlands and Yorkshire Ambulance Services, covering 10.6 million people. The cohort included 38,010 injured patients of any age conveyed by land or air ambulance. This phase was published in the Emergency Medicine Journal in May 2026, alongside an economic evaluation and further questionnaires and focus groups.
What they found
The phase two validation, published in PLoS ONE in March 2026 with 2,607 patients and 928 reference-positive cases, found a weighted major trauma prevalence of 3.1%. The MATTS specific tool had sensitivity of 37.3% and specificity of 95.1%, closest to the team’s targets. The balanced version scored 58% and 87%, the sensitive version 72% and 76%. Existing service tools ranged from 32% to 51% sensitivity and 86% to 95% specificity. A companion paper in the Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine in 2024 showed that actual crew decisions in the same period achieved 46.7% sensitivity and 94.5% specificity, because clinicians were not simply following checklists.
In the live evaluation, 2.2% of the 38,010 patients (838) had major trauma. Real-world triage decisions had sensitivity of 55.3% (95% CI 51.8% to 58.7%) and specificity of 94.3% (95% CI 94.1% to 94.6%). Positive predictive value was 18.0% and negative predictive value 98.9%. Fewer than one in five patients pre-alerted to an MTC had major trauma, and 99 in 100 taken elsewhere did not need expedited MTC care.
In the West Midlands, sensitivity rose from 48.3% before implementation to 59.0% after, with specificity falling from 97.7% to 96.0%. In Yorkshire, decisions were unchanged at 51.2% to 51.3%. Sensitivity was 42.3% in patients aged 65 and over, 65.7% in adults aged 16 to 64 and 67.7% in children. Rural and urban performance was similar.
Uptake was the weak point. Clear evidence of tool use was found in only 6.3% of patients, and use was unclear in 65.5%. Senior clinical advice was sought in 9.3%. Focus groups found crews used the tool mainly when uncertain, or as a tick box to confirm a decision already made. It had been introduced without a dedicated training programme. Costs (£149) and benefits (0.006 quality-adjusted life years) were similar across tools in practice. On theoretical performance, MATTS cost £21,163 per QALY gained.
Strengths and limitations
This is a large, multi-service UK evaluation with a consensus-based reference standard, national registry linkage and a design that tested the tool on paper and then in practice.
Phase three ran in only two services, and the authors note that differences in MTC configuration, physician availability and service organisation may limit generalisability. It relied on routine records, so poor documentation may have been read as non-use. Phase two sample sizes differ between publications (2,607 and 2,757). The economic case rests on theoretical performance the tool did not reach in practice. The validated tools were adult tools; the authors list paediatric triage, pre-alerting and remote clinical support as future work.
What it means for your practice
- Paramedics and ambulance clinicians: Keep using your service’s current tool unless it changes. The authors say clinician education and further evaluation are needed before national roll-out. Take the logic: at 2% prevalence, a degree of under-triage is accepted so that MTCs are not overwhelmed. Watch the age gap. Sensitivity was lowest in patients aged 65 and over, and in validation it was lowest for low-energy mechanisms, at 29.5%.
- Offshore and diver medics: You do not bypass hospitals, but you decide who needs a medevac now and who can wait. The MATTS reference standard, built on need for time-critical intervention rather than mechanism alone, is a useful lens. Remote decision support in the tool mirrors your topside doctor. Use it early, not as a tick box.
- First responders: Your role is recognition and clean handover. Physiology and obvious anatomical injury are the first two steps of the tool. Report them accurately, with times, and flag age and anticoagulant use.
Do not change destination thresholds, pre-alert criteria or scene times on the basis of this study. Local trauma network protocols and JRCALC govern practice.
Reflect
- When did you last override a triage tool, and what information drove that decision?
- In your setting, what are the real costs of over-triage and under-triage, and which do you fear more?
- How does your assessment of an older patient after a low-energy fall differ from a younger patient after a road collision?
- If a national tool arrived with no training attached, what would you need in order to use it consistently?
Read the original
- Emergency Medicine Journal, Accuracy of major trauma triage using the MATTS tool: a cohort study, 2026
- Health Technology Assessment, Developing a national triage tool for use in NHS regional trauma networks: the MATTS mixed methods study, 2026
- PLoS ONE, Major Trauma Triage Study (MATTS): Diagnostic accuracy of major trauma triage tools in English regional trauma networks, 2026
- Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine, The accuracy of prehospital triage decisions in English trauma networks: a case-cohort study, 2024
- Major Trauma Triage Tool Study (MATTS) expert consensus-derived injury assessment tool, development paper
- University of Sheffield, MATTS project overview
- Health Research Authority, MATTS research summary
- ISRCTN registry, MATTS: Major Trauma Triage Tool Study, ISRCTN17968752
Published 25 October 2026. Last reviewed October 2026.
These summaries are for education and CPD only. They are not clinical guidelines. Always practise within your scope of practice and follow your employer’s protocols and national guidance such as JRCALC and Resuscitation Council UK.