Table 3.

Descriptions of Diagnosis Disagreement between the BAT-L and CTBIE

Category	Number of Cases	Description	Example(s)
Errors	8	Explicit factual mistake in one or the other assessment	Two cases received positive diagnoses based on the CTBIE despite the fact that the CTBIE report explicitly stated that those individuals did not experience the signs necessary for diagnosis according to the DoD criteria. Six cases were negative for TBI diagnosis despite that the CTBIE specifically noted that the patient experienced the signs associated with a concussion.
Inconsistent Reporting	11	The Veteran reported different signs across assessments	Veterans denied any TBI signs at one assessment, but reported them at the other (3 false positives and 8 false negatives).
Confounding Factors	5	Circumstances surrounding the injury may have clouded the Veteran’s interpretation of his/her symptoms	One Veteran reported feeling confused after a blast woke him up in the middle of the night. This was considered AMS based on the CTBIE; however when further queried on the BAT-L, he reported that he was able to respond appropriately/perform duties as expected within seconds of awakening. His confusion was thought to be related to being awoken during a chaotic situation rather than related to acute AMS caused by a TBI.
PCS vs TBI Diagnostic Criteria	3	Veterans reported PCS, but did not report acute AMS, PTA, or LOC at the time of the injury	Veterans denied any signs of TBI at the time of their injury, but reported symptoms such as headaches, dizziness, and memory problems persisting after the incident. These symptoms are often secondary to other causes, such as the stress or chaos of the combat situation, dehydration, lack of sleep, etc.