Comorbidity associated with traumatic brain injury disability among US Army disability cases: 2005-2010

Traumatic brain injury (TBI) is a major cause of disability among soldiers. However, the contribution of TBI and the related comorbidities to disability is not well understood. All active duty soldiers evaluated for TBI-related disability in FY2005-2010 were included. Individuals with a Veteran's Administration Schedule of Ratings (VASRD) code of 8045 were defined as TBI cases (n=2,823). TBI cases were classified into groups based on the presence of other VASRD codes for mental health conditions at time of evaluation. Inpatient diagnoses listed in medical records generated within two years of disability evaluation were examined for each TBI case group. Overall, 30% of TBI cases were hospitalized in the two years prior to disability evaluation. Hospitalization was most common in TBI cases with comorbid PTSD (40%). Skull fractures were the most prevalent inpatient diagnosis, but were more prevalent in TBI cases without comorbid psychiatric conditons. Concussions were more prevelant in TBI with comorbid psychiatric conditions. Deployment was most common in those with TBI and PTSD (99%) and these cases were most likely to have inpatient psychiatric diagnoses. Clinical patterns and deployment history vary when comparing TBI cases in terms of psychiatric comorbid disability. Understanding the role of deployment, combat exposures, and pre-existing medical conditions in the risk of TBI disability with and without psychicatric morbidity is essential to reduce the morbidity associated with TBI in service members and to target interventions for soldiers who experience a TBI.