Defining major trauma using the 2008 Abbreviated Injury Scale

Area of Science:

• Trauma research
• Injury scoring systems
• Public health surveillance

Background:

• The Injury Severity Score (ISS) is a standard metric for trauma severity.
• The traditional ISS >15 threshold, based on AIS98, may require reevaluation due to updates in the Abbreviated Injury Scale (AIS) codeset (AIS08).

Purpose of the Study:

• To determine appropriate ISS and New Injury Severity Score (NISS) thresholds for the 2008 AIS (AIS08).
• To compare the predictive accuracy of these new thresholds for mortality and resource use against the established ISS >15 (AIS98) benchmark.

Main Methods:

• Analysis of 37,760 patient records from a state trauma registry.
• Mapping of 1998 AIS (AIS98) data to AIS08 for ISS and NISS calculation.
• Assessment of various ISS and NISS thresholds' ability to predict mortality and high-level resource utilization (ICU or urgent surgery).

Main Results:

• An ISS >12 using AIS08 demonstrated comparable patient classification and mortality rates to ISS >15 using AIS98.
• A NISS >15 threshold showed similar performance to the ISS thresholds.
• The AIS08-based ISS >12 threshold offered superior classification accuracy across all assessed severity measures compared to NISS >15.

Conclusions:

• An ISS >12 threshold with AIS08 coding serves as a suitable replacement for ISS >15 with AIS98 in identifying patients at elevated risk of death.
• Adopting an ISS >12 threshold for AIS08 can enhance major trauma patient identification in mortality-focused trauma surveillance.