Preliminary study of hearing protection and non-impact, blast-induced concussion in US military personnel.

PRIMARY OBJECTIVE: To examine the relationship between hearing protection and non-impact, blast-induced concussion in US military personnel. RESEARCH DESIGN: Retrospective cohort study. METHODS AND PROCEDURES: A total of 501 US service members from the Expeditionary Medical Encounter Database with hearing protection status reported either 'worn' or 'not worn' were eligible for analysis. Clinical records were reviewed for concussion diagnoses. Univariate and multiple logistic regressions were performed. MAIN OUTCOMES AND RESULTS: Overall, 270 (53.9%) service members sustained non-impact, blast-induced concussion and 231 (46.1%) sustained other blast injuries. Only 39.6% (107 of 270) of service members with concussion wore hearing protection at the point of injury compared with 61.0% (141 of 231) of those with other injuries (p < 0.001). After adjusting for covariates, service members wearing hearing protection had significantly lower odds of concussion compared with those not wearing hearing protection (odds ratio = 0.42, 95% confidence interval = 0.29-0.62). CONCLUSIONS: To our knowledge, this preliminary study is the first to demonstrate that hearing protection is associated with lower odds of non-impact, blast-induced concussion. The benefits of using hearing protection in terms of force readiness could be significant since many service members wounded in recent conflicts were diagnosed with concussion.

Treatment of Mental or Physical Health Problems in a Combat Zone: Comparisons of Postdeployment Mental Health and Early Separation From Service.

The primary aim of this study was to evaluate whether being treated for mental health or nonbattle physical injury during military combat deployment was associated with higher risk for postdeployment mental disorders and poorer career outcomes than seen in the general combat-deployed population. Service members treated in theater for mental health (n = 964) or noncombat injury (n = 853) were compared with randomly sampled personnel (n = 7,220) from the general deployed population on diagnosed mental disorders and early separation from service. Deployment, medical, and career information were obtained from Department of Defense archival databases. Over half of the personnel who received mental health treatment while deployed were diagnosed with 1 or more mental disorders postdeployment and/or were separated from service before completing their full-term enlistment. This was significantly higher than expected compared to the general deployed group, adjusting for demographic/military characteristics and mental health history (adjusted odds ratios [ORs] ranging 1.62 to 2.96). Frequencies of problems also were higher in the mental health-treated group than in the group treated for nonbattle physical injuries (significant adjusted ORs ranging 1.65 to 2.58). The documented higher risks for postdeployment adjustment problems suggested that especially those treated in theater by mental health providers might benefit from postdeployment risk-reduction programs.

Repeated concussion among U.S. military personnel during Operation Iraqi Freedom.

Concussions are a predominant injury of the conflicts in Iraq and Afghanistan. The aims of this study were to describe repeated concussive events among U.S. military personnel injured in Operation Iraqi Freedom and examine subsequent healthcare utilization. We reviewed clinical records from the Expeditionary Medical Encounter Database to identify service members with repeat concussions. We abstracted demographic and injury-specific variables, calculated time between events, and identified healthcare utilization from electronic medical databases. Overall, 113 personnel experienced more than one concussion between 2004 and 2008. A majority of these incidents were blast related. The median time between events was 40 days, with 20% experiencing a second event within 2 weeks of the first and 87% within 3 months. Time between events was not associated with severity of the second event. Greater severity of the second concussive event was associated with higher postinjury utilization of mental health and neurology services. This study is one of the first to describe repeated concussions in a combat setting. We found that repeated concussions occur within a short interval among deployed personnel, although the effects of the first event are unclear. Further research is needed to define the effect of repeated concussions on the health of combat veterans.

Battlefield extremity injuries in Operation Iraqi Freedom.

OBJECTIVE: Extremity injuries account for the majority of wounds incurred during US armed conflicts. Information regarding the severity and short-term outcomes of patients with extremity wounds, however, is limited. The aim of the present study was to describe patients with battlefield extremity injuries in Operation Iraqi Freedom (OIF) and to compare characteristics of extremity injury patients with other combat wounded. PATIENTS AND METHODS: Data were obtained from the United States Navy-Marine Corps Combat Trauma Registry (CTR) for patients who received treatment for combat wounds at Navy-Marine Corps facilities in Iraq between September 2004 and February 2005. Battlefield extremity injuries were classified according to type, location, and severity; patient demographic, injury-specific, and short-term outcome data were analysed. Upper and lower extremity injuries were also compared. RESULTS: A total of 935 combat wounded patients were identified; 665 (71%) sustained extremity injury. Overall, multiple wounding was common (an average of 3 wounds per patient), though more prevalent amongst patients with extremity injury than those with other injury (75% vs. 56%, P<.001). Amongst the 665 extremity injury patients, 261 (39%) sustained injury to the upper extremities, 223 (34%) to the lower extremities, and 181 (27%) to both the upper and lower extremities. Though the total number of patients with upper extremity injury was higher than lower extremity injury, the total number of extremity wounds (n=1654) was evenly distributed amongst the upper and lower extremities (827 and 827 wounds, respectively). Further, lower extremity injuries were more likely than the upper extremity injuries to be coded as serious to fatal (AIS>2, P<.001). CONCLUSIONS: Extremity injuries continue to account for the majority of combat wounds. Compared with other conflicts, OIF has seen increased prevalence of patients with upper extremity injuries. Wounds to the lower extremities, however, are more serious. Further research on the risks and outcomes associated with extremity injury is necessary to enhance the planning and delivery of combat casualty medical care.