1. Measuring Trauma Outcomes Injury Severity Score (ISS) Probability of Survival (Ps17) Hospital Survival rate (Ws) BOAST4 Chest Wall Injury report The Trauma Audit & Research Network (TARN)

2. Injury Coding Ensuring coding uniformity
Injury coding performed centrally at TARN
Ensuring coding uniformity
Coders check injury descriptions & imaging reports
Abbreviated Injury Scale dictionary (AIS2005) currently used
Every submission assigned an Injury Severity Score (ISS)
75,000 submissions per year coded

3. Abbreviated Injury Scale: AIS
THE Internationally recognised system for injury scoring
Produced by AAAM (Association for the Advancement of Automotive Medicine) in U.S.A
Introduced in 1970, originally for Vehicle Crash investigators
AIS2005 version >2000 injury descriptors
Anatomically based system, ranking injuries according to severity on a 6 point ordinal scale

4. AIS: 6 point severity scale
Grade
Injury example 1
Minor
Bruise to abdomen 2
Moderate
Small Liver laceration 3
Serious
Liver laceration with >1 litre of blood loss 4
Severe
Ruptured liver 5
Critical
Liver laceration involving hepatic vessels 6
Maximum
Avulsed liver

5. It’s not a disability scale
AIS Severity indicates
The relative risk of “threat to life”
in an average person
who sustains the coded injury
as his or her only injury
It’s not a disability scale

6. AIS code structure: 7 digits
Injury
Numerical identifier
Severity Score
Comminuted Femoral Shaft #
853271 .3
Large Subdural haemorrhage
140656 .5

7. Abbreviated Injury Scale: Sections
Skin
Degloving
Penetrating
Hypothermia
Crush
Asphyxia: Hanging/Strangulation
Traumatic Amputation
Drowning
Nerve
Frostbite
Vessel
Burns
Joint
Inhalation
Skeletal
Electrocution

8. AIS: Spinal Injuries Cervical Spine (C1-C7) Thoracic Spine (T1-T12)
Lumbar spine (L1-L5)
Severity can be affected by location of spinal injury

9. AIS: Confirmed injuries only
Suspected injuries 
Possible injuries 
Probable injuries 
Ruled out injuries 

10. AIS: Not Coded Infections Pneumonia Death Blindness Miscarriage
Epilepsy following head injury
Pulmonary embolism following skeletal injury
Don’t affect Severity score

11. NFS: Not Further Specified
This appears throughout the AIS dictionary & allows the coding of injuries when detailed information is lacking
Example:
Injury description = Liver laceration
Coded as: (Liver laceration NFS)

12. AIS 6 not used just because a patient dies!
AIS 6: Maximum score
AIS 6 not used just because a patient dies!
Has to be documented medical evidence of an AIS 6 injury

13. AIS 6: Maximum score Head or Neck
Brain stem: laceration, crush, penetrating or transection
C3 or higher complete cord transection or contusion
Sigmoid or Transverse sinus or Internal carotid artery: Bilateral lacerations
Thorax
Heart: rupture, multiple lacerations or avulsion
Total chest crush
Aortic rupture + haemorrhage not confined to mediastinum
Bilateral pulmonary artery or vein transection
Severe inhalation
Abdominal & Pelvic contents
Liver avulsion
External
2nd or 3rd degree burns > 90% Total Body Surface
Massive Whole body Explosion type injury

14. AIS: Localisers 2 additional localiser codes, allow coding of:
Localiser 1 Side or aspect of an injury
e.g. Right, left, Upper, Temporal, Frontal
Localiser 2 Actual Site of an injury
e.g. 5th rib, 12th Thoracic vertebrae, 2nd toe
Numerical identifier
Severity
Localiser 1
Localiser 2
Don’t affect ISS
Used mainly in Research

15. AIS dictionary Available only from: www.aaam.org
Latest Version: AIS 2015 recently released
$225 each + shipping
TARN will moving to AIS2015 at end of year
All existing codes will be mapped over
All Trusts notified well in advance

16. Injury Coding exercise

17. EXAMPLE SUBMISSION 1: INJURIES Page AIS code
Spiral Shaft of Femur
147
Open complete articular fracture to distal Radius
127
Open book fracture to pelvis with blood loss >20%
159
3 ribs fractured on left 82
Extensive bilateral cerebral contusion 44
Skull vault fracture 49
Grade III (OIS grade) Spleen laceration 96

18. Calculating the ISS
Injury Severity Score

19. Calculating the ISS: Step 1
Determine the scores of the individual injuries using the Abbreviated Injury Scale

20. Identify the highest severity score in each body area
Calculating the ISS: Step 2
Identify the highest severity score in each body area

21. Injury Severity Score: 6 body areas
Head & Neck & Cervical spine
Face
Chest & Thoracic spine
Abdomen & pelvic contents & Lumbar spine
Extremities & bony pelvis
External (incl. Skin injuries and Burns)

22. Head Thorax Abdomen Extremities Extensive bilateral cerebral contusion
Skull vault fracture
Thorax
3 ribs fractured on left
Abdomen
Grade III Spleen laceration
Extremities
Open complete articular fracture to distal Radius
Open book fracture to pelvis with blood loss >20%
Spiral Shaft of Femur

23. Square the highest score in each body area
Calculating the ISS: Step 3
Square the highest score in each body area

24. Head 5² =25 Thorax 3² =9 Abdomen 3² =9 Extremities 5² = 25
Extensive bilateral cerebral contusion
Skull vault fracture
Thorax
3 ribs fractured on left
Abdomen
Grade III Spleen laceration
Extremities
Open complete articular fracture to distal Radius
Open book fracture to pelvis with blood loss >20%
Spiral Shaft of Femur
5² =25
3² =9
3² =9
5² = 25

25. Calculating the ISS: Step 4
Code individual injuries
Identify the highest score in each body area
Square the highest score in each body area
Add together the highest AIS2 from 3 different body areas

26. Head 5² =25 Thorax 3² =9 Abdomen 3² =9 Extremities 5² = 25
Extensive bilateral cerebral contusion
Skull vault fracture
Thorax
3 ribs fractured on left
Abdomen
Grade III Spleen laceration
Extremities
Open complete articular fracture to distal Radius
Open book fracture to pelvis with blood loss >20%
Spiral Shaft of Femur
5² =25
3² =9
3² =9
5² = 25

27. Injury Severity Score
(ISS) = 59

28. Injury Severity Score (ISS)
Body area
Injury
AIS code
Head
Closed vault fracture
Thorax
5+6 ribs fractured on left
2² = 4
2² = 4
This patient has 3 different injuries.
2 body regions injuries
Highest scores are 9 (Thorax) and 4 (Head). ISS = 13
ISS = 8

29. Injury Severity Score (ISS)
Body area
Injury
AIS code
Head
Closed vault fracture
Thorax
5+6 ribs fractured on left
External
Lower limb – skin laceration
2² = 4
2² = 4
1² = 1
This patient has 3 different injuries.
2 body regions injuries
Highest scores are 9 (Thorax) and 4 (Head). ISS = 13
ISS = 9

30. Injury Severity Score (ISS)
Ranges from 1 to 75
Maximum 75 achieved in 2 ways:
Severity 5 in 3 different body areas
= 75
ISS convention:
AIS = 6 in any body area, ISS = 75

31. Importance of Injury Detail
Length, depth or Grade of lacerations (especially to internal organs)
Depth, size and location of haemorrhages and contusions (especially in the brain)
Open or Closed fractures
Stability & site of Fractures (e.g. Comminuted/Displaced Shaft/Proximal/Distal fracture)
Articular (joint) involvement (e.g. Intra-articular, extra-articular)
Blood loss
Vessel damage
Location & number of rib fractures
Compression or effacement of ventricles/brain stem cisterns
Neurology associated with spinal cord injuries
Grade, Instability, Blood loss or Vascular damage associated with Pelvic Fractures
Cardiac arrest associated with asphyxia or drowning
Ensure all injuries are documented
Include imaging reports or Post Mortems for every submission.
Jan 17: Grade now requested for pelvic ring fixations

32. Probability of Survival
Once ISS is assigned
Probability of Survival (Ps) calculated each submission

33. Why calculate PS? Need to assign weight to deaths and survivors.
Some deaths more statistically significant than others.
Case mix adjustment.
Performances measurement: hospital and networks.

34. Charlson comorbidity index adds ‘weighting’ PMC
Ps history
TARN developed first Ps model in 2004
Remodelled in 2007, 2009, 2012, 2014 and 2017
Components used in Ps since 2014 (best predictors of outcome):
ISS
Age
Gender
GCS
Pre-Existing Medical Conditions (PMC)
Charlson comorbidity index adds ‘weighting’ PMC

35. i $ Ps17 (launched July 17) Age Gender ISS GCS/ intubation PMC
Ps17 calculation $
Patient PS: 63% *
*Charlson index (1984, revised).

36. What is Ps?
PS% is retrospective measure of pts with same profile on TARN database.
TARN database: past 4 years (Approx 300,000 cases)
Ps = 63%, then 63 out of every 100 patients with that profile have previously survived.
37 out of every 100 patients have previously died.

37. Probability of Survival
Ps is calculated using:
GCS taken on arrival in ED at first receiving hospital
where unavailable
Pre Hospital GCS
Presence of Intubation/ventilation
Impute a “probable” GCS (equivalent weighting)

38. Pre-Existing Medical Conditions
Ps17 Weighting groups
Pre-Existing Medical Conditions
Weight
PMC group
Bone conditions
Connective tissue disorder
GU/GI disease
Neurological disorders
No PMC
Other
Paraplegia
Pulmonary disease
1-5
Alcohol abuse
Blood conditions
Cancer
CVA
Dementia
Diabetes
Heart failure
HIV
Mental health MI
Renal disease
Vascular disease
6-10
Haematological malignancy
Liver disease
Metastatic cancer

39. Weightings for Age, GCS, Gender & PMC
Ps17
Weightings for Age, GCS, Gender & PMC
Age: 25
Gender: Male
ISS: 25
GCS: 15
PMC:
Nil i
Ps17 calculation $
Ps: 99.2%

40. Weightings for Age, GCS, Gender & PMC
Ps17
Weightings for Age, GCS, Gender & PMC
Age: 25
Gender: Male
ISS: 25
GCS: 15
PMC:
Alcohol abuse i
Ps17 calculation $
Ps: 98.6%

41. Weightings for Age, GCS, Gender & PMC
Ps17
Weightings for Age, GCS, Gender & PMC
Age: 25
Gender: Male
ISS: 25
GCS: 15
PMC:
Alcohol Abuse
Liver Disease i
Ps17 calculation $
Ps: 95.7%

42. Weightings for Age, GCS, Gender & PMC
Ps17
Weightings for Age, GCS, Gender & PMC
Age: 25
Gender: Male
ISS: 25
GCS: 3
PMC:
Alcohol Abuse
Liver Disease i
Ps17 calculation $
Ps: 21.6%

43. Weightings for Age, GCS, Gender & PMC
Ps17
Weightings for Age, GCS, Gender & PMC
Age: 65
Gender: Male
ISS: 25
GCS: 3
PMC:
Alcohol Abuse
Liver Disease i
Ps17 calculation $
Ps: 4.7%

44. Weightings for Age, GCS, Gender & PMC
Ps17
Weightings for Age, GCS, Gender & PMC
Age: 65
Gender: Female
ISS: 25
GCS: 3
PMC:
Alcohol Abuse
Liver Disease i
Ps17 calculation $
Ps: 5.09%

45. Importance of accurate injury detail
Ps17
Importance of accurate injury detail
Full injury detail
Code
Spiral Shaft of Femur
Open complete articular fracture to distal Radius
Open book fracture to pelvis with blood loss >20%
3 ribs fractured on left
Extensive bilateral cerebral contusion
Skull vault fracture
Grade III (OIS grade) Spleen laceration
Accurate ISS
Accurate Ps 59
58%
Incomplete injury detail
Code
Spiral Shaft of Femur
Fracture to distal Radius
Fracture to pelvis
Multiple ribs fractured on left
Cerebral contusion
Skull vault fracture
Spleen laceration
Incomplete ISS 22
White text= change in severity
Italics= used in ISS calculation

46. Importance of accurate injury detail
Ps17
Importance of accurate injury detail
Age: 40
Gender: Male
ISS: 22
GCS: 5
PMC:
Nil i
Ps17 calculation $
Ps: 86%

47. PS breakdown: shown on website & clinical reports (more later)
Ps Bandings
No. of patients in each band
Observed/Actual survivors
Expected survivors (compared to TARN database)
Difference = Observed – Expected x 100
No. in group
Ws = Difference x fraction of patients on database in each band
Hospital Survival Rate= 0.67 additional survivors per 100 patients
95% Confidence interval
Ws lies between this line

48. Individual Hospital Survival Rate shown on website: English & Welsh sites only
+1.2 Survivors
Statistically significant outcome
(+0.39 to +1.97)
+1.2 Survivors
Not Statistically significant
(-1.83 to +4.2)

49. Comparative Survival rate (Ws) shown in Clinical report:
All hospitals
Your hospital
95% confidence intervals

50. Funnel plots: Greater Precision: More cases
Potential outlier (positive)
Normal range
All hospitals
Greater Precision: More cases
(more reliable)
Lower Precision: Fewer cases
(not as reliable)
Hospitals shown by Precision (no. of cases)
Ws must always be viewed in conjunction with Case ascertainment

51. Highlighting patients for Ws review
Produce a Performance Review Indicators report (PRI) & review data in negative Ps bands: Particularly the deaths using the Data Quality Report

52. Example patients to review: Ps:45-65%
Age
Sex
ISS
GCS
Int
Outcome
PMC
Mechanism
Injuries
Submission ID
46.2% 46
Male 16 3
Yes
Death
N/K
Fall >2m
Skull Vault #
SDH NFS (AIS4)
Brain swelling
With large SDH & Liver disease: ISS= 25, Ps= 28% Ps
Age
Sex
ISS
GCS
Int
Outcome
PMC
Mechanism
Injuries
Submission ID
57.7% 94
Female 38 14 No
Death
N/K
Fall <2m
T cord transection (AIS5)
BOS # (AIS3)
Pelvic # (AIS2)
With GCS 3 & Dementia: Ps= 3%

53. The Performance Review Indicators report

54. Performance Review Indicators Includes Approved cases only
Highlights Key Performance Measures that underpin TARN reports
Submission ID
NHS number
Age
Gender
Injury Mechanism
ISS & ISS band
GCS
Intubation
Probability of Survival
Outcome at 30 days
Incident date/time
Arrival date/time
Discharge date
LOS
ICU LOS
Transfer from/to
Mode of arrival
PROMS Available
Trauma Team
Senior Dr in ED Date/Time
First Dr in ED Date/Time
No of Operations
Date/time 1st Operation
Time to 1st Operation
Date/Time 1st CT
Time to 1st CT
Incident & Home postcodes
Triage Tool
Pre Alert
PRF
Wards visited (first 2)
Visited ED
NICE criteria
Shocked Patient (SBP<110)
Rehab Prescription
GOS
Case for Review
Most severely injured body region
Maximum AIS
All Injuries
01/04/16 -31/03/17
St Marys or St George’s

55. Analysing your own data using PRI Report
Create a PRI report
List specific patients e.g.
Ps bands: To review
AIS3+ Head injuries CT within 1 hour
ISS 16+ who saw a Consultant
Produce a breakdown

56. Severe Open fractures of Tibia: Gustilo Anderson grade 3b or 3c
BOAST 4
Guidelines derived from BOA & BAPRAS
Severe Open fractures of Tibia: Gustilo Anderson grade 3b or 3c
Guideline requires:
Early identification of severe open fractures of the tibia
Joint care from orthopaedic & plastic surgeons
Surgical wound debridement & operative fracture stabilisation within 24 hours
Definitive soft-tissue cover within 72 hours of injury
BOAST 4 report shows compliance with standard

57. Chest Wall Injuries
Patients with chest wall injuries (fracture of rib/s and/or sternum)
Proportion of:
>3 ribs fractured
chest wall fixations
Attendances by pain team
Lists all injuries coded
All 01/04/17 -31/07/17

58. Questions