The Problem with KSI: Using Trauma Data to Analyse Injury Severity Matt Staton

1. 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

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

3. The 4th ‘E’

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

5. Trauma

6. 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

7. CTARP Data 39,763 STATS 19 Persons ‘injured’ 2,850 ONS Registered deaths 3,307 PHEMS Attended patients 3,383 TARN Submitted cases 2,020 Do not meet entry criteria 38,526 Do not meet entry criteria 1,237 Meet entry criteria 2,464 Do not meet entry criteria 384 Meet entry criteria 2,682 Do not meet entry criteria 625 Meet entry criteria 1,363 Meet entry criteria 254 Pre-hospital deaths 983 Survivors to hospital 261 Pre-hospital deaths 123 Survivors to hospital 186 Pre-hospital deaths 439 Survivors to hospital 329 Pre-hospital deaths 1,685 Survivors to hospital 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

8. CTARP Data Pre-hospital Deaths - 329 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

9. CTARP Data Survivors to hospital - 1685 ONS (123) 35 21 1 2 20 PHEMS (439) 21 TARN (1363) 15 8 1 592 50 386 271 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

10. 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)

11. Epidemiology 12 (11 to 13 ) 22 (20 to 23 ) 34 (32 to 36) Age-standardised population rate per 100,000 (95% CI)

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

13. 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.

14. 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

15. CTARP ‘KSI’ Data 39,763 persons (from 17,256 incidents) 15,897 uninjured and 1 unborn child excluded STATS19 persons Five years - 2000 to 2004 inclusive 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) 2083 ‘serious’ (1548 resident / 536 non-resident) Cambridgeshire Trauma Audit and Research Project 20,532 ‘slight’

16. CTARP ‘KSI’ Data Cambridgeshire Trauma Audit and Research Project

17. CTARP Responsibility Data All persons Cambridgeshire Trauma Audit and Research Project

18. CTARP Responsibility Data Responsible persons Cambridgeshire Trauma Audit and Research Project

19. CTARP Responsibility Data • 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

20. 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

21. We need to act on these lessons…

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