title: Major incident triage: Derivation and comparative analysis of the Modified Physiological Triage Tool (MPTT).
abstract: BACKGROUND
  Triage is a key principle in the effective management at a major incident. There are at least three different triage systems in use worldwide and previous attempts to validate them, have revealed limited sensitivity. Within a civilian adult population, there has been no work to develop an improved system.
  
  
  METHODS
  A retrospective database review of the UK Joint Theatre Trauma Registry was performed for all adult patients (>18years) presenting to a deployed Military Treatment Facility between 2006 and 2013. Patients were defined as Priority One if they had received one or more life-saving interventions from a previously defined list. Using first recorded hospital physiological data (HR/RR/GCS), binary logistic regression models were used to derive optimum physiological ranges to predict need for life-saving intervention. This allowed for the derivation of the Modified Physiological Triage Tool-MPTT (GCS≥14, HR≥100, 12<RR≥22). A comparison of the MPTT and existing triage tools was then performed using sensitivities and specificities with 95% confidence intervals. Differences in performance were assessed for statistical significance using a McNemar test with Bonferroni correction.
  
  
  RESULTS
  Of 6095 patients, 3654 (60.0%) had complete data and were included in the study, with 1738 (47.6%) identified as priority one. Existing triage tools had a maximum sensitivity of 50.9% (Modified Military Sieve) and specificity of 98.4% (Careflight). The MPTT (sensitivity 69.9%, 95% CI 0.677-0.720, specificity 65.3%, 95% CI 0.632-0.675) showed an absolute increase in sensitivity over existing tools ranging from 19.0% (Modified Military Sieve) to 45.1% (Triage Sieve). There was a statistically significant difference between the performance (p<0.001) between the MPTT and the Modified Military Sieve.
  
  
  CONCLUSIONS
  The performance characteristics of the MPTT exceed existing major incident triage systems, whilst maintaining an appropriate rate of over-triage and minimising under-triage within the context of predicting the need for a life-saving intervention in a military setting. Further work is required to both prospectively validate this system and to identify its performance within a civilian environment, prior to recommending its use in the major incident setting.
authors.affiliation: Division of Emergency Medicine, University of Cape Town, Cape Town, South Africa; Institute of Naval Medicine, Gosport PO12 2DL, United Kingdom. Electronic address: vassallo@doctors.org.uk.
authors.forename: James
authors.initials: J
authors.lastname: Vassallo
authors.affiliation: Faculty of Science and Technology, Bournemouth University, Bournemouth, United Kingdom. Electronic address: jbeavis@bournemouth.ac.uk.
authors.forename: John
authors.initials: J
authors.lastname: Beavis
authors.affiliation: Academic Department of Military Emergency Medicine, Royal Centre for Defence Medicine (Research & Academia), Medical Directorate, Joint Medical Command, Birmingham, United Kingdom. Electronic address: jasonesmith@nhs.net.
authors.forename: Jason E
authors.initials: JE
authors.lastname: Smith
authors.affiliation: Division of Emergency Medicine, University of Cape Town, Cape Town, South Africa. Electronic address: lee.wallis@bvr.co.za.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Wallis
mesh_terms: D015998:Abbreviated Injury Scale; D000328:Adult; D000066491:Clinical Decision-Making / Q000379:methods; D004189:Disaster Planning / Q000458:organization & administration*; D004632:Emergency Medical Services / Q000592:standards; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D016015:Logistic Models; D008297:Male; D054527:Mass Casualty Incidents; D010343:Patient Admission; D012189:Retrospective Studies; D014218:Triage / Q000592:standards; D006113:United Kingdom / Q000453:epidemiology; D014947:Wounds and Injuries / Q000401:mortality / Q000628:therapy; D055815:Young Adult
keywords: Life-saving intervention; Major incidents; Physiological predictors; Triage