The Problem with KSI: Using Trauma Data to Analyse Injury Severity Matt Staton Cambridgeshire County Council Road Safety GB Analysis Conference - Joining the Dots 2 March 2017

Overview Understanding Major Trauma Different severity definitions What can we learn from it?

The 4th ‘E’ Engineering Education (ETP) Enforcement Epidemiology

East of England Trauma Network Trauma System East of England Trauma Network www.eoetraumanetwork.nhs.uk

Trauma Fatal injuries Injuries requiring hospitalisation or resulting in disability Injuries treated in emergency department setting Injuries treated in primary care setting Injuries that do not receive attention in a healthcare setting

Trauma System Epidemiology Population based Multi-agency Injury Research Register (5 years) 100% case ascertainment Complete epidemiological description Mechanism Injury patterns Pre-hospital care Emergency care Outcomes (pre-hospital and in-hospital) Socio-demographic profile Cambridgeshire Trauma Audit and Research Project

Do not meet entry criteria CTARP Data 39,763 STATS 19 Persons ‘injured’ 2,850 ONS Registered deaths 3,307 PHEMS Attended patients 3,383 TARN Submitted cases 254 Pre-hospital deaths 983 Survivors to hospital 38,526 Do not meet entry criteria 1,237 Meet entry criteria 2,020 1,363 2,682 625 186 439 2,464 261 123 384 329 1,685 150 In-hospital deaths Entry criteria: Kinetic injury event within the geographical County of Cambridgeshire between 2000 and 2004 and resulting in a pre-hospital trauma death (with injuries which would have met TARN injury criteria) or survival to hospital with admission that met TARN 07 entry criteria Cambridgeshire Trauma Audit and Research Project

CTARP Data Pre-hospital Deaths - 329 ONS STATS19 PHEMS (261) STATS19 (254) PHEMS (186) Entry criteria: Kinetic injury event within the geographical County of Cambridgeshire between 2000 and 2004 and resulting in a pre-hospital trauma death (with injuries which would have met TARN injury criteria) or survival to hospital with admission that met TARN 07 entry criteria Cambridgeshire Trauma Audit and Research Project

CTARP Data Survivors to hospital - 1685 Cambridgeshire Trauma Audit ONS (123) 35 21 1 2 20 PHEMS (439) 21 TARN (1363) 15 8 1 592 50 271 386 85 177 STATS 19 (983) Entry criteria: Kinetic injury event within the geographical County of Cambridgeshire between 2000 and 2004 and resulting in a pre-hospital trauma death (with injuries which would have met TARN injury criteria) or survival to hospital with admission that met TARN 07 entry criteria Cambridgeshire Trauma Audit and Research Project

Epidemiology Burden of Disease (Count of patients, 95% CI)1 Pre-hospital System Survive to hospital Admitted with significant injury (meeting UK TARN entry criteria) 2 Age-standardised population rate per 100,000 (95% CI) 3 999 Call 2623 4 Serious injury 55 (53-57) Survival to hospital 46 (42-48) Serious Injury 34 (32-36) Severe Injury (ISS >8) 22 (20-23) Major Trauma (ISS > 15) 12 (11-13) Cambridgeshire Trauma and Research Project See www.tarn.ac.uk Directly age-standardised rate per 100,000 resident population with 95% confidence interval Based on estimate from Ambulance Service related to 999 call burden for trauma related AMPDS codes (150000/year)

Epidemiology 12 (11 to 13 ) 22 (20 to 23 ) 34 (32 to 36) EoE ITSPB 20 April 2010 Epidemiology Major Trauma ISS > 15 ‘Severe’ Injury ISS > 8 TARN entry criteria 12 (11 to 13 ) 22 (20 to 23 ) 34 (32 to 36) Age-standardised population rate per 100,000 (95% CI) R Mackenzie 11

Epidemiology Road traffic collisions remain the commonest cause of severe injury or life threatening major trauma

STATS19 ‘serious injury’ Serious injury: An injury for which a person is detained in hospital as an “in-patient”, or any of the following injuries whether or not they are detained in hospital: fractures, concussion, internal injuries, crushings, burns (excluding friction burns), severe cuts, severe general shock requiring medical treatment and injuries causing death 30 or more days after the accident. An injured casualty is recorded as seriously or slightly injured by the police on the basis of information available within a short time of the accident. This generally will not reflect the results of a medical examination, but may be influenced according to whether the casualty is hospitalised or not. Hospitalisation procedures will vary regionally.

Trauma Network injury severity Injury Severity Score (ISS) Worst 3 injuries to 6 body regions using the Abbreviated Injury Scale (AIS) Top 3 scores are squared and added together Score >8 – severe injury Score >15 – major trauma Injury severity Example AIS code Minor Minor laceration 1 Moderate Simple rib/sternal fracture 2 Serious Open long bone fracture 3 Severe Limb amputation 4 Critical Spine injury with quadriplegia 5 Maximum Total severance of aorta 6

CTARP ‘KSI’ Data 39,763 persons STATS19 persons (from 17,256 incidents) STATS19 persons Five years - 2000 to 2004 inclusive 15,897 uninjured and 1 unborn child excluded 23,865 persons 334 ‘killed’ 2924 ‘serious’ 20,594 ‘slight’ 1064 discharged from ED 254 STATS19 pre-hospital deaths (172 resident, 82 non-resident) 80 STATS19 in-hospital deaths (<30 days) (64 resident, 16 non-resident) 1860 1019 with LoS < 72 hrs and/or injuries which do not meet CTARP/TARN entry criteria 841 ‘serious’ + 2 in-hospital STATS19 death initially coded as serious and slight (both resident) 62 met TARN entry criteria, 1 of which was an in-hospital death + 61 patients coded as slight -1 of which is in-hospital death 336 ‘killed’ (238 resident / 98 non-resident)``````` 901 ‘severe’ TARN entry criteria (697 resident / 286 non-resident) Cambridgeshire Trauma Audit and Research Project 2083 ‘serious’ (1548 resident / 536 non-resident) 20,532 ‘slight’

CTARP ‘KSI’ Data Cambridgeshire Trauma Audit and Research Project

CTARP Responsibility Data All persons Cambridgeshire Trauma Audit and Research Project

CTARP Responsibility Data Responsible persons Cambridgeshire Trauma Audit and Research Project

CTARP Responsibility Data To blame (n=123) Whole group (n= 281) Significance (p) Median age (IQR) 35 (22-49) 34 (22-49) p=0.9 Mean Age (SD) 38 (20-58) 38 (19-57) Modal Age 30 18 P=0.02 Proportion male (%) 76 47 P=0.005 43% of those with ISS>15 following road traffic collisions were not responsible for the injury event Injury prevention strategies targeted according to the epidemiology of the injured may not effectively target those who cause injury events Cambridgeshire Trauma Audit and Research Project

Trauma System Lessons Learned Multi-agency data sharing improves understanding ‘Serious injury’ in STATS19 terms doesn’t necessarily constitute a ‘severe injury’ in trauma care or injury prevention terms Linking TARN and STATS19 data will provide the cheapest, quickest and most comprehensive understanding of road traffic related injury. Existing prevention strategies, if targeted on injured road user profiles, may not be effectively targeted at high-risk or culpable road users. Cambridgeshire Trauma Audit and Research Project

We need to act on these lessons… Engineering Education (ETP) Enforcement Epidemiology

Contact matt.staton@cambridgeshire.gov.uk @statonmatt