Major incident triage: comparative validation using data from 7th July bombings

Introduction: The importance of health service planning for major incident management has been recognised since the World Trade Centre attacks of September 2001 and is highly relevant to planning for the 2012 Olympics. UK national Major Incident guidance stipulates the use of a system of triage for casualties to prioritise treatment and ensure "the greatest good for the greatest number". However, at least three triage systems are in use worldwide and no evidence exists to demonstrate their relative efficacy. The transport bombings in London on 7th July 2005 caused the largest number of casualties on mainland UK soil since World War 2. We aimed to validate three major incident triage systems using patient data from the 7th July bombings.

Patients and methods: A retrospective cohort of patients from the 7th July bombings treated at the Royal London Hospital (RLH) was examined. Clinical information collected on arrival at RLH was used to allocate triage categories using the START, Manchester Sieve and CareFlight triage systems. The value of each system in identifying the critically injured patient was calculated.

Results: 203 sets of records were examined. Outcome data was available for 166 patients, of whom 8 were critically injured. Of these 166 patients, triage categories could be retrospectively allocated for 124 (START), 127 (Manchester Sieve), 128 (CareFlight), including 4 of the critically injured. All three systems identified the same three patients as P1 or P2. The triage systems performed identically in identifying the critically injured, with sensitivity 50% and specificity 100% if using only the highest priority, or sensitivity 75% and specificity 99% if using the top 2 priority groups. Significant amounts of data were not recorded in prehospital and hospital notes.

Discussion and conclusions: Systematic triage of mass casualties is effective but the amount of missing data seriously compromises any attempt to evaluate systems of trauma care in a major incident.