Traumatic brain injury: It is all about definition

Area of Science:

• Trauma research
• Epidemiology
• Clinical assessment

Background:

• Traumatic brain injury (TBI) definitions vary, impacting research consistency.
• Existing methods may prioritize immediate clinical use over epidemiological accuracy.
• The Abbreviated Injury Score (AIS) shows potential for TBI severity classification if cut-offs are optimized.

Purpose of the Study:

• To determine optimal Abbreviated Injury Score (AIS) cut-off points for defining traumatic brain injury (TBI) severity.
• To promote uniformity in future traumatic brain injury (TBI) epidemiological studies.

Main Methods:

• Analysis of mortality rates across different Abbreviated Injury Score (AIS) categories for TBI patients.
• Evaluation of predictive discrimination of various AIS cut-off points.
• Assessment of Glasgow Coma Scale (GCS) limitations in identifying TBI severity, especially with missing data or multiple injuries.

Main Results:

• Mortality rates for TBI with AIS 3 and 4 were 1.9% and 2.9%, respectively, versus 31.1% for AIS 5+.
• An AIS cut-off of 5+ demonstrated superior predictive discrimination for TBI severity.
• Missing GCS data or normal GCS scores did not preclude serious or critical TBI, highlighting limitations of GCS alone.

Conclusions:

• Recommends adopting an Abbreviated Injury Score (AIS) cut-off of ≥ 5 for defining severe traumatic brain injury (TBI) in epidemiological research.
• Suggests classifying AIS 3-4 as 'moderate' TBI and AIS 1-2 as 'mild' TBI.
• Emphasizes the need for standardized definitions to improve TBI research and understanding.