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Accident Injury Severity - Indian Institute of Technology...
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Accident Injury Severity
Transcript of Accident Injury Severity - Indian Institute of Technology...
Accident
Injury Severity
Accident Severity
Collision severity
Injury severity
Early Severity Scales
Burden of injury – live or dead
Live - bleeding or not bleeding
Injured – treated or not treated
Treated – physician, doctor’s office
emergency room
released or admitted
Injury Severity
Department of Transport
Fatal Injury - injuries which caused death in
less than 30 days after the accident.
Serious Injury - inpatient or fracture,
concussion, internal injuries, crushings,
severe cuts, severe shock type of injury or
death after 30 days.
Slight Injury - minor sprain, bruise, cut, or
requiring only roadside attention
WORKING DEFINITIONS OF
A FATALITY Greece, Portugal, Spain use within 24
hours.
France uses within 6 days.
Italy uses within 7 days.
Most other states use within 30 days.
Correction Factors applied to get 30 day
equivalent, range from 1.3 (Spain) to
1.078 (Italy).
Serious & Slight
Prone to error
severity assessed and
assigned by police at the
scene
Correct in ≈ 60% of cases
Therefore a better scale is
needed which could be
used by non medics and
the scale that is
anatomically based
Abbreviated Injury Scale
Developed in the 1960’s by a group of 75
specialists from around the world.
Introduced in 1971
Revised in 1980, 1985, 1990,1998 & 2005
Abbreviated Injury Scale
Probability of threat to
life scale based on
individual injury
7 digit code
used to classify an injury.
123456.7
The code describes
type of injury
location of injury
severity of injury
Abbreviated Injury Scale
123456.7
1 Body Region
2 Type of Anatomical Structure
3/4 Specific Anatomical Structure
5/6 Level
7 Severity Score
1 Body Region 123456.7
1 Head
2 Face
3 Neck
4 Thorax
5 Abdomen
6 Spine
7 Upper Extremity
8 Lower Extremity
9 Unspecified
2 Type of Anatomic Structure 123456.7
1 Whole Area
2 Vessels
3 Nerves
4 Organs (inc. muscles/ligaments)
5 Skeletal (inc. joints)
6 Loss of Consciousness (head only)
3/4 Specific Anatomic Structure 123456.7
Whole Area
02 Skin Abrasion
04 Contusion
06 Laceration
08 Avulsion
10 Amputation
20 Burn
30 Crush
40 Degloving
50 Injury - NFS
60 Penetrating
Head - Loss of Consciousness (LOC)
02 Length of LOC
04-08 Level of Consciousness
10 Concussion
Spine
02 Cervical
04 Thoracic
06 Lumbar
Vessels, Nerves, Organs, Bones, Joints
These are all assigned consecutive
two digit numbers beginning with 02
5/6 Level
123456.7
Specific Injuries are assigned
consecutive two-digit numbers
beginning with 02
Fractures, rupture, laceration, etc
Injury Severity
Abbreviated Injury Score
1 Minor
2 Moderate
3 Serious
4 Severe
5 Critical
6 Maximum
AIS
AIS Example
1 superficial laceration
2 fractured sternum
3 open fracture of humerus
4 perforated trachea
5 ruptured liver with tissue loss
6 total severance of aorta
AIS – Threat to life
AIS % prob. of death
1 0
2 1 – 2
3 8 – 10
4 - 5 50 – 50
6 100
Organ injuries
Skeletal injuries
Measures of Injury Severity
• Maximum Abbreviated Injury Score (MAIS) - Maximum AIS for an occupant or body region
- Frequently used for assessing overall severity
- Non-linear relationship with the probability of death
Body region AIS MAIS
Head 4
Neck 2
Thorax 5 5
Abdomen 1
Lower limb 3
Injury Severity Score (ISS)
Gives a better fit between overall severity &
probability of survival than MAIS
The ISS is the sum of the squares of the
highest AIS code in each of the three most
severely injured ISS body regions.
There six ISS body regions.
Six ISS body regions
Head or Neck
Face
Thorax
Abdominal or Pelvic content
Extremities or Pelvic Girdle
External
Injury Severity Score (ISS)
Body region AIS MAIS Head 4 Neck 2 Thorax 5 5 Abdomen 1 Lower limb 3
ISS = (5x5)+(4x4)+(3x3) = 50
ISS range 0 – 75
Proviso : AIS 6 = ISS 75
Linear scale 0 - 75
Examples
Uses
of
Injury Severity Data
• Eppinger et al (1999) (NHTSA)
• Foret-bruno et al (1998) 42nd STAPP
• Mertz
(1971??)
