measuring trauma outcomes
TRANSCRIPT
Measuring Trauma Outcomes
Injury Severity Score (ISS)Probability of Survival (Ps19)
Hospital Survival rate (Ws)
Virtual
The Trauma Audit & Research Network (TARN)
TARN
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)
90,000+ submissions per year coded
Injury Coding
TARN
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
TARN
AIS: 6 point severity scale
AIS(Severity)
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
TARN
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
TARN
AIS code structure: 7 digits
Code Injury Numerical identifier
Severity Score
853271.3 Comminuted Femoral Shaft # 853271 .3
140656.5 Large Subdural haemorrhage 140656 .5
TARN
Abbreviated Injury Scale: Sections
Skin Degloving
Penetrating Hypothermia
Crush Asphyxia: Hanging/Strangulation
Traumatic Amputation Drowning
Nerve Frostbite
Vessel Burns
Joint Inhalation
Skeletal Electrocution
TARN
AIS: Spinal Injuries
Cervical Spine (C1-C7) Thoracic Spine (T1-T12) Lumbar spine (L1-L5)
Severity can be affected by location of spinal injury
TARN
AIS: Confirmed injuries only
Suspected injuries
Possible injuries
Probable injuries
Ruled out injuries
TARN
AIS: Not Coded
Infections
Pneumonia
Death
Blindness
Miscarriage
Epilepsy following head injury
Pulmonary embolism following skeletal injury
Don’t affect Severity score
TARN
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: 541820.2 (Liver laceration NFS)
TARN
Most used NFS codeswhich affect data accreditation
Most used NFS codes Information needed
Cerebrum/cerebellum contusionDiameter of the contusion or a description of the size e.g.
tiny, small, large, extensive.
Cerebrum/cerebellum subdural/extradural The depth of the haematoma or a description of the size e.g.
tiny, small, large, extensive confirmed in imaging
Cerebrum/cerebellum intracerebral haematomaDiameter of the ICH or a description of the size e.g. tiny,
small, large, extensive.
Brain swelling
Severity of the swelling e.g mild; sulcal effacement, moderate; compressed or partially effaced ventricles, major;
effaced ventricles
Multiple rib fractures Number of ribs fractured and which side the fracture are on
Long bone fractures e,g clavicle, femur & fibular Location of the fracture e.g. proximal, shaft, distal.
Facial fractures e.g. zygoma, orbit Location of the fracture
TARN
AIS 6: Maximum score
AIS 6 not used just because a patient dies!
Has to be documented medical evidence of an AIS 6 injury
TARN
AIS 6: Maximum score Head or Neck
Brain stem: laceration, crush, penetrating or transectionC3 or higher complete cord transection or contusionSigmoid 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
TARN
AIS: Localisers2 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
• Don’t affect ISS• Used mainly in Research
TARN
AIS dictionary
Available only from: www.aaam.org
• Latest Version: AIS 2015 recently released • $225 each + shipping• TARN will be moving to AIS2015• All existing codes will be mapped over • All Trusts notified well in advance
TARN
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
853251.3
752372.3
856164.5
450203.3
140626.5
150400.2
544224.3
EXAMPLE SUBMISSION: INJURIES Page AIS code
TARN
Calculating the ISSInjury Severity Score
TARN
Calculating the ISS: Step 1
Determine the scores of the individual injuries using the
Abbreviated Injury Scale
TARN
Calculating the ISS: Step 2
Identify the highest severity score in each body areaTARN
Injury Severity Score: 6 body areas
1. Head & Neck & Cervical spine
2. Face
3. Chest & Thoracic spine
4. Abdomen & pelvic contents & Lumbar spine
5. Extremities & bony pelvis
6. External (incl. Skin injuries and Burns)
TARN
Head Extensive bilateral cerebral contusion 140626.5
Skull vault fracture 150400.2
Thorax 3 ribs fractured on left 450203.3
Abdomen Grade III Spleen laceration 544224.3
Extremities Open complete articular fracture to distal Radius 752372.3
Open book fracture to pelvis with blood loss >20% 856164.5
Spiral Shaft of Femur 853251.3
TARN
Calculating the ISS: Step 3
Square the highest score in each body area
TARN
Head Extensive bilateral cerebral contusion 140626.5
Skull vault fracture 150400.2
Thorax 3 ribs fractured on left 450203.3
Abdomen Grade III Spleen laceration 544224.3
Extremities Open complete articular fracture to distal Radius 752372.3
Open book fracture to pelvis with blood loss >20%856164.5
Spiral Shaft of Femur 853251.3
5² =25
3² =9
3² =9
5² = 25
TARN
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
TARN
Head Extensive bilateral cerebral contusion 140626.5
Skull vault fracture 150400.2
Thorax 3 ribs fractured on left 450203.3
Abdomen Grade III Spleen laceration 544224.3
Extremities Open complete articular fracture to distal Radius 752372.3
Open book fracture to pelvis with blood loss >20%856164.5
Spiral Shaft of Femur 853251.3
5² =25
3² =9
3² =9
5² = 25
TARN
Injury Severity Score(ISS) = 59
TARN
ISS = 8
Injury Severity Score (ISS)Body area Injury AIS code
Head Closed vault fracture 150402.2
Thorax 5+6 ribs fractured on left 450202.2
2² = 4
2² = 4TARN
ISS = 9
Injury Severity Score (ISS)Body area Injury AIS code
Head Closed vault fracture 150402.2
Thorax 5+6 ribs fractured on left 450202.2
External Lower limb – skin laceration 810600.1
2² = 4
2² = 4
1² = 1TARN
Injury Severity Score (ISS)
Ranges from 1 to 75
Maximum 75 achieved in 2 ways:
1. Severity 5 in 3 different body areas
52 + 52 + 52 = 75
2. ISS convention:
AIS = 6 in any body area, ISS = 75
TARN
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 fracturesStability & site of Fractures (e.g. Comminuted/Displaced Shaft/Proximal/Distal fracture)
Articular (joint) involvement (e.g. Intra-articular, extra-articular)
Blood loss Vessel damageLocation & number of rib fractures Compression or effacement of ventricles/brain stem cisternsNeurology 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 documentedInclude imaging reports or Post Mortems for every submissionTransfers: Paste imaging reports from previous hospital into injury descriptionRadiology Guidance Doc- Resources page
Imaging can be inconclusive: “Almost certainly post-traumatic or spontaneous, cannot exclude significant underlying venous sinus thrombosis”
TARN
Probability of Survival
Once ISS is assigned
Probability of Survival (Ps) calculated eachsubmission
TARN
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.
TARN
Ps history
TARN developed first Ps model in 2004
Remodelled in 2007, 2009, 2012, 2014, 2017 and 2019
Components used in Ps since 2014 (best predictors of outcome):
ISS Age Sex GCS
Pre-Existing Medical Conditions (PMC)
Charlson comorbidity index adds ‘weighting’ PMC
TARN
Ps19 (launched July 19)
Age Sex ISSGCS/
intubationPMC
i i i i i
Ps19 calculation
$
Patient PS: 63%
*
*Charlson index (1984, revised).
TARN
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.
TARN
Ps is calculated using:
GCS taken on arrival in ED at first receiving hospital
where unavailable
Pre Hospital GCS where unavailable
Presence of Intubation/ventilationwhere unavailable
Impute a “probable” GCS (equivalent weighting)
Probability of Survival
TARN
Ps19 Weighting groups Pre-Existing Medical Conditions
0 Bone conditionsConnective tissue disorderGU/GI diseaseNeurological disorders
No PMCOtherParaplegiaPulmonary disease
1-5 Alcohol abuseBlood conditionsCancerCVADementiaDiabetes
Heart failureHIVMental healthMIRenal diseaseVascular disease
6-10 Haematological malignancyLiver disease
Metastatic cancer
Weight PMC group
TARN
Ps19 Importance of accurate injury detail
Full injury detail Code
Spiral Shaft of Femur 853251.3
Open complete articular fracture to distal Radius 752372.3
Open book fracture to pelvis with blood loss >20% 856164.5
3 ribs fractured on left 450203.3
Extensive bilateral cerebral contusion 140626.5
Skull vault fracture 150400.2
Grade III (OIS grade) Spleen laceration 544224.3
Incomplete injury detail Code
Spiral Shaft of Femur 853251.3
Fracture to distal Radius 752371.2
Fracture to pelvis 856151.2
Multiple ribs fractured on left 450210.2
Cerebral contusion 140604.3
Skull vault fracture 150400.2
Spleen laceration 544220.2
Accurate ISS Accurate Ps
59 58%
Incomplete ISS
22
Inaccurate Ps
86%
TARN
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
TARN
Individual Hospital Survival Rate shown on website: English & Welsh sites only
+1.2 SurvivorsStatistically significant outcome
(+0.39 to +1.97)
+1.2 SurvivorsNot Statistically significant
(-1.83 to +4.2)
TARN
Comparative Survival rate (Ws) shown in Clinical report: Trauma Units
95% confidence intervals
All hospitals
Your hospital
TARN
Funnel plots: Major Trauma Centres only
Hospitals shown by Precision (no. of cases)Ws must always be viewed in conjunction with Case ascertainment
Lower Precision: Fewer cases (not as reliable)
Greater Precision: More cases (more reliable)
Normal range
All hospitals
Potential outlier (positive)
Alert: 2 SDAlarm: 3 SD
TARN
Negative Ps Bands: more deaths than expected
Produce a Performance Review Indicators report (PRI) & review data in negative Ps bands: Particularly the deaths using the Data Quality Report >>>>
Highlighting patients for Ws review
We work with hospitals to conduct a Ws review where they have been identified as an outlierBased on financial year figures
TARN
Example patients to review: Ps:45-65%
With large SDH & Liver disease: ISS= 25, Ps= 28%
With GCS 3 & Dementia: Ps= 3%
On review both these patients would move out of the 45-65 Ps band, and into lower Ps bands, where we expect more patients to die.
Ps 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
999900004552
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)
999900004517
TARN
Moving Ps Bands
If data had been entered correctly the patients would not be in the 45-65 Ps band:
Ps BandNumber in band
ObservedSurvivors
Expected Survivors
DifferenceTARN
fractionWs
45-65 79 45 44.24 0.76 0.03 0.02
Total Ws 0.72
TARN
The Performance Review Indicators reportTARN
Performance Review IndicatorsIncludes Approved cases only
Highlights Key Performance Measures that underpin TARN reports
Submission IDNHS number
AgeSex
Injury MechanismISS & ISS band
GCSIntubation
Probability of SurvivalOutcome at 30 daysIncident date/timeArrival date/time
Discharge date LOS
ICU LOSTransfer from/toMode of arrival
PROMS AvailableTrauma Team
Senior Dr in ED Date/TimeFirst Dr in ED Date/Time
No of OperationsDate/time 1st Operation
Time to 1st OperationDate/Time 1st CT
Time to 1st CTIncident & Home postcodes
Triage Tool
Pre AlertPRF
Wards visited (first 2)Visited ED
NICE criteriaShocked Patient (SBP<110)
Rehab PrescriptionGOS
Case for ReviewMost severely injured body
region Maximum AIS
All Injuries
TARN
Analysing your own data using PRI Report
Create a PRI report- Date for Selection: Arrival date
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
Link to submissions
TARN
Major Trauma PROMs Patient reported outcome measures
TARN
Background
TARN collects patient outcome data at discharge or 30 days.
Previously, little understanding of long term impact of Major Trauma on return to
work or education.
12 month DOH funded MT PROMS feasibility launched : Autumn 2014
19 MTCs involved initially
Children’s MT PROMs launched January 2015
Study continued: Now all MTCs, CMTCs, 1 Welsh site & 1 TU involved
Trusts asked to include ISS >15 patients, but can include all TARN eligible.
TARN
The PROMs process
PROMs are short questionnaires completed by patients or carers.
Measure the patients’ perception of their health status at a single point in time.
PROMs questionnaire (Q1) is given to patients in hospital when stable.
Follow-up Q2 questionnaire (Q2) sent to patients via post at 6 months post discharge. TARN
Processing the data
NHS-E Accredited PROMS supplier: Quality Health process PROMs data.
PROMs and TARN data linkage then performed.
Reports produced by TARN every quarter.
Uploaded to website Identify pts reporting serious to extreme problems at 6 months. Trusts can then follow these patients up. PROMS guidance document on website
Data download also available from TARN website quartery>>>>>
TARN
PROMS: Data download
Uploaded on TARN website Secure log in required 2 nominated PROMS contacts per Trust TARN submission IDs included in Excel file TARN
34%
26%
19%
16%
3% 2%
Patients that were working, looking after family or studying before incident Same work
Unable to work or work in shelteredworkshop
Same work but some problems
Work at a reduced level
Not recorded
Ability to work changed but not due to injury
PROMs figures: Change in ability to work at 6 months
61% change in ability to work
TARN
Change in patient’s ability to look after themselves at 6 months
59%20%
11%
7%
2% 1%
I do not need
I need some help in the home, but not every day
I could look after myself for at least 8 hours ifnecessaryI could not look after myself for 8 hours during thedayI need help in the home, but not because of theinjuryNot stated
38% of patients = change to their independence
TARN