Using harmonized FITBIR datasets to examine associations between TBI history and cognitive functioning.

Demonstrate how patient-level traumatic brain injury (TBI) data from studies in the Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System can be harmonized and pooled to examine relationships between TBI and cognitive functioning. We harmonized and pooled data across studies and analyzed rates of probable cognitive functioning deficits by TBI history and severity. Four publicly available FITBIR studies with 3,445 participants included data on cognitive dysfunction, though only one included comparison groups (mild TBI vs. no history of TBI) and could be used in the final comparative analyses. Of the 1,539 participants, 82% had a history of mild TBI and 67% had data suggesting the presence of cognitive dysfunction. Participants with a history of mild TBI were mostly male (87%), 25-39 years old (53%), and Non-Hispanic White (60%).