Harmonizing Federal Interagency Traumatic Brain Injury Research Data to Examine Depression and Suicide-Related Outcomes

Objective: This proof-of-concept study was conducted to establish the feasibility of compiling Federal Interagency Traumatic Brain Injury Research (FITBIR) data pertaining to depression and suicide risk, with the secondary goal of improving understanding regarding these outcomes. FITBIR is a national repository of participant-level traumatic brain injury (TBI) data designed to address methodological limitations (e.g., small sample size, heterogeneity of injuries). Method: FITBIR studies with TBI severity and measures related to depression and suicidal ideation were identified. Data were harmonized across relevant studies and grouped to identify "probable depression" and suicidal ideation, resulting in a large, combined sample. Rates of probable depression and suicidal ideation were described across the available studies, considering the influence of demographic and/or injury-related factors on outcomes. Results: Cross-sectional studies meeting criteria included four studies with depression outcomes and two with suicidal ideation outcomes. Two studies reported data appropriate for comparative analyses on depression. Combined results suggested that approximately 71% of participants were categorized as having probable depression. Participants with a history of mild TBI had 2.54 greater odds of probable depression (95% confidence interval [1.93, 3.34]) than those without a history of TBI. Conclusions: Methods, harmonization code, and meta-databases related to TBI, probable depression, and suicidal ideation are now publicly available on the FITBIR website. Even with limited data, harmonization of FITBIR studies can serve as the basis for ongoing TBI and mental health research. Analyses will be more robust in the future as more studies with relevant outcome data are added to the FITBIR database. Impact and ImplicationsThis study demonstrates the feasibility of harmonizing participant-level data from Federal Interagency Traumatic Brain Injury Research (FITBIR) into a single meta-database. Participants with mild traumatic brain injury (TBI) had greater odds of meeting criteria for probable depression than those without TBI. Methodological products including harmonization and data-analysis code and the TBI depression meta-data set have been made publicly available through the FITIBIR website.