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

ABSTRACT

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.

KEYWORDS:

• Blast
• combat
• concussion
• hearing protection
• injury
• military

Declaration of Interest

The authors report no conflicts of interest.

Disclaimer

I am a military service member (or employee of the U.S. Government). This work was prepared as part of my official duties. Title 17, USC, §105 provides the ‘Copyright protection under this title is not available for any work of the United States Government’. Title 17, USC, §101 defines a U.S. Government work as work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties. The views expressed in this research are those of the authors and do not necessarily reflect the official policy or position of the Department of the Navy, Department of the Army, Department of the Air Force, Department of Veterans Affairs, Department of Defense, or the U.S. Government. This research has been conducted in compliance with all applicable federal regulations governing the protection of human subjects in research (Protocol NHRC.2003.0025).

Additional information

Funding

This work was supported by the U.S. Navy Bureau of Medicine and Surgery under the Wounded, Ill, and Injured/Psychological Health/Traumatic Brain Injury Program, Work Unit No. 60808.