Associations between operationally estimated blast exposures and postdeployment diagnoses of postconcussion syndrome and posttraumatic stress disorder.

Traumatic brain injuries and other blast-related injuries have been identified as the signature injury of the wars in Iraq and Afghanistan. Some operational units in Iraq, especially those responsible for clearing roadways, were exposed to hundreds of blast incidents and thousands of individual doses of concussive energy during their lengthy deployments. Using operational records maintained by a single command element, the researchers conducted a retrospective cohort study evaluating the association between estimated individual exposures to blasts and the risk for postconcussion syndrome (PCS) and posttraumatic stress disorder (PTSD). Tactical records documented all of the relevant details of the subjects' exposures to blasts during their missions. During the study period there were 313 blasts involving 418 service members resulting in 4,250 blast person events. Of that population, 12.9% were diagnosed with PCS, 8.6% with PTSD, and 5.3% with both. This study suggests that estimating the total individual dosage to concussive forces through physical evidence at the scene could be a useful predictor of future brain-disorder diagnoses. Those in vehicles sustaining heavy blast damage are at increased risk of being diagnosed with PTSD with a rate ratio of 2.79 (95% CI, 1.27-6.13) and PTSD in conjunction with PCS with a rate ratio of 4.10 (95% CI, 1.63-10.28). Standardization of the data collection method for blast incidents and additional follow-up studies could lead to the development of better ways of monitoring operational risk factors for negative health outcomes, plans to intervene in order to minimize health risks, and establish customized follow-up protocols based on specific dosage thresholds.