Health Phenotypes and Neurobehavioral Symptom Severity Among Post-9/11 Veterans With Mild Traumatic Brain Injury: A Chronic Effects of Neurotrauma Consortium Study.

The study was cross-sectional, so it could not tell whether symptoms affected health trajectories or health trajectories affected symptoms. The study did not have injury dates, and the Comprehensive TBI Evaluation was completed on average 25.8 months after Veterans initiated VA care, with a median of 14 months. The phenotype groups were created using data that could have included the time of the Comprehensive TBI Evaluation and Neurobehavioral Symptom Inventory. Depression and PTSD diagnoses were used to build the phenotypes, so the study did not adjust for them separately or test whether they modified associations. The sample includes only Veterans who used the Veterans Health Administration, so it may not represent all post-9/11 Veterans with mild traumatic brain injury. Possible over-reporting was handled by excluding 9,332 Veterans (12.8%) with Validity-10 scores greater than 22; 22.3% of Polytrauma Veterans were excluded, and the authors warn this cut point may remove Veterans with the most complex histories. The study did not describe details of care or test treatments, so it cannot show which intervention would reduce symptoms or interference.

The authors declared no conflicts of interest.

Do not read the association between Polytrauma and severe symptoms as evidence that treating these symptoms will improve health trajectories. The study was observational and cross-sectional, did not test interventions, and could not separate symptom timing from health trajectories. Also, 22.3% of Polytrauma Veterans exceeded the Validity-10 over-reporting cut point.