Long-term Mental Health Trajectories of Injured Military Servicemembers: Comparing Combat to Noncombat Related Injuries

Objective: We sought to quantify the impact of injury characteristics and setting on the development of mental health conditions, comparing combat to noncombat injury mechanisms. Background: Due to advances in combat casualty care, military service-members are surviving traumatic injuries at substantial rates. The nature and setting of traumatic injury may influence the development of subsequent mental health disorders more than clinical injury characteristics. Methods: TRICARE claims data was used to identify servicemembers injured in combat between 2007 and 2011. Controls were servicemembers injured in a noncombat setting matched by age, sex, and injury severity. The rate of development, and time to diagnosis [in days (d)], of 3 common mental health conditions (post-traumatic stress disorder, depression, and anxiety) among combat-injured servicemembers were compared to controls. Risk factors for developing a new mental health condition after traumatic injury were evaluated using multivariable logistic regression that controlled for confounders. Results: There were 3979 combat-injured servicemember and 3979 matched controls. The majority of combat injured servicemembers (n = 2524, 63%) were diagnosed with a new mental health condition during the course of follow-up, compared to 36% (n = 1415) of controls (P < 0.001). In the adjusted model, those with combat-related injury were significantly more likely to be diagnosed with a new mental health condition [odds ratio (OR): 3.18, [95% confidence interval (CI): 2.88-3.50]]. Junior (OR: 3.33, 95%CI: 2.66-4.17) and senior enlisted (OR: 2.56, 95%CI: 2.07-3.17) servicemem-bers were also at significantly greater risk. Conclusions: We found significantly higher rates of new mental health conditions among servicemembers injured in combat compared to service-members sustaining injuries in noncombat settings. This indicates that injury mechanism and environment are important drivers of mental health sequelae after trauma.