The Boston Assessment of Traumatic Brain Injury-Lifetime (BAT-L) semistructured interview: evidence of research utility and validity

Abstract

Objective: Report the prevalence of lifetime and military-related traumatic brain injuries (TBIs) in Operation Enduring Freedom and Operation Iraqi Freedom (OEF/OIF) veterans and validate the Boston Assessment of TBI-Lifetime (BAT-L).

Setting: The BAT-L is the first validated, postcombat, semistructured clinical interview to characterize head injuries and diagnose TBIs throughout the life span.

Participants: Community-dwelling convenience sample of 131 OEF/OIF veterans.

Design: TBI criteria (alteration of mental status, posttraumatic amnesia, and loss of consciousness) were evaluated for all possible TBIs, including a novel evaluation of blast exposure.

Main measures: BAT-L, Ohio State University TBI Identification Method (OSU-TBI-ID).

Results: About 67% of veterans incurred a TBI in their lifetime. Almost 35% of veterans experienced at least 1 military-related TBI; all were mild in severity, 40% of them were due to blast, 50% were due to some other (ie, blunt) mechanism, and 10% were due to both types of injuries. Predeployment TBIs were frequent (45% of veterans). There was strong correspondence between the BAT-L and the OSU-TBI-ID (Cohen κ = 0.89; Kendall τ-b = 0.95). Interrater reliability of the BAT-L was strong (κs >0.80).

Conclusions: The BAT-L is a valid instrument with which to assess TBI across a service member's lifetime and captures the varied and complex nature of brain injuries across OEF/OIF veterans' life span.

Figures

Figure 1

Consensus diagnosis of most severe lifetime TBI by severity in 131 OEF/OIF veterans. The number of veterans who sustained a grade I mTBI, grade II mTBI, grade III mTBI, moderate TBI, or severe TBI for each category of injury is reported. mTBI indicates mild traumatic brain injury; OEF/OIF, Operation Enduring Freedom and Operation Iraqi Freedom.

Figure 2

Total number of military TBIs (blast and other mechanism combined) by severity in 131 OEF/OIF veterans. All military injuries were mTBIs. The percentage of veterans experiencing a military grade I, II, or III injury is reported. mTBI indicates mild traumatic brain injury; OEF/OIF, Operation Enduring Freedom and Operation Iraqi Freedom; TBI, traumatic brain injury.