External causes of traumatic brain injury, 2000-2011.

This report summarizes frequencies, distributions, and trends of external causes of traumatic brain injuries (TBIs) that are recorded on standardized records of medical encounters of U.S. military members. Causes of TBI were reported for 100 percent of cases hospitalized in military facilities, but were relatively infrequently reported in other treatment settings (i.e., military outpatient facilities, combat theater and civilian medical facilities). During 2008-2011 in all clinical settings combined, 24,115 service members had TBI case-defining medical encounters with recorded injury causes. Accidents represented 74 percent of recorded causes; the most frequently reported specific causes were motor vehicle traffic accidents (20%), falls (20%), and being struck by or struck against an object (15%). Similar proportions of TBIs were reportedly due to intentional "assaults" unrelated to war (11%) and "battle injuries" (11%). Assaults were second only to motor vehicle accidents as reported causes of TBIs treated in civilian hospitals. Some TBIs reportedly due to accidents with guns/explosives were likely combat injuries that were miscoded in military hospitals. The doubling of the number of combat-related TBIs reported from Iraq/Afghanistan between 2010 and 2011 undoubtedly reflects the U.S. military's increased focus on identifying and treating TBIs among deployed military members.