# Presentation: 680242

## Abbreviated Injury Scale

- Measures of severity
- ICE on injury statistics
- Maria Segui-Gomez

## Agenda

- Brief history
- Uses and overuses
- Advantages/limitations over other severity measures
- 	common criticisms

## Disclaimer

- I was a member of the AAAM Injury Scaling Committe from 1999-2003 and now I am back on it

## The AIS is

- An anatomically based,
- consensus derived,
- global severity scoring system
- that classifies each injury in every body region
- according to its relative importance on a six point ordinal scale

- T. Genarelli, AAAM annual meeting 2003

## Purposes of AIS

- Describe injuries anatomically
- Standardize injury terminology
- Rank injuries by severity
- Facilitate comparisons of injury studies

## History

- 1971 AAAM and SAE get together to develop a tool that will allow injury and injury severity characterization for physicians and motor vehicle engineers
- Injury severity defined as a mix of death threat, energy dissipation, disability, duration of treatment and incidence of injury
- In 1974, first release with approximately 70 injuries given severity scores ranging 1-6

## Several revisions leading up to AIS 1985 were current format was adopted

## AIS 1990 (with 1998 update) well extended
AIS 2005 just released.
Expansion in format
Incorporation of Orthopedic Trauma Association codes for fractures
6.1 (2+2)   2000 codes (and them some)
Allows for specification of aspect and others

- AIS 2005 just released.
- Expansion in format
- Incorporation of Orthopedic Trauma Association codes for fractures
- 6.1 (2+2)   2000 codes (and them some)
- Allows for specification of aspect and others

## Over time things have...

- ...remained constant:
- Pre dot injury descriptor
- Post dot severity descriptor
- Severity range 0-6
- Expert assessment of severity

- ..or changed:
- Definition of severity –narrowed to threat to life
- Expanded to non motor vehicle injuries (e.g., burns)
- Expanded to pediatric injuries
- Expanded to include LOC for brain injury –only exception to anatomic basis

## Overall

- Produced centrally by AAAM
- Used in all in-depth crash investigation efforts in US and Europe (NASS CDS, CIREN, CCIS, German database) and in many more in other continents
- Bases for motor vehicle regulation in US, Canada, Australia, Japan and Europe
- Used in some 1600 papers since 1975 avaliable throug Pub Med and many more engineering papers not available trhough Pub Med
- Available in English, Spanish, Chinese, French, German, Italian
- Certification for coding in place in US –plans to extend abroad

## Some big helpers

- Mapping from ICD-9-CM to AIS85 introduced AIS to massive health-related databases such as hospital discharge data
- Updated to AIS1990 (update 1998)
- Other “maps” available in several Trauma Registry software packages
- Its body region classification has been widely adopted (maybe until arrival of Barell matrix)

## Common Criticisms

- Expert assement (as in subjective, poor)
- Same severity score does not mean the same in different body regions
- Presumes otherwise healthy individual, up to standard health care, single injuries
- You have to buy a license
- There is no map for ICD-10

## But

- Not all injuries are sufficiently frequent in real world databases
- On actual comparison of AIS and death at hospital discharge (as printed in AIS 2005 manual):

- Data from NTR -ACS

## And...

- Same severity score does not mean the same in different body regions ?¿?¿
- Presumes otherwise healthy individual, up to standard health care, single injuries
- You have to buy a license.  Yes, 190$ each
- There is no map for ICD-10. No, we just finished one to AIS-98! Plans to map to AIS05 underway

## Head to Head comparison

- AIS
- Expert assement
- Broader definition of time to death
- Single injury, can combine
- Universal

- ICISS
- Empirically based
- If hospital, death to discharge, if death certificate...
- Each injury goes in with whichever proportion of other injuries are present (and reported)
- Which version? Which country? Which datasource? Which year?

- Both are anatomically based, assign severity to some 2000 descriptors,
- ignore many other confounders (for death)

## In sum

- No perfect measure
- Not perfect for all and every use
- But at least common language across disciplines and countries