Epidemiology of Hearing Impairment and Noise-Induced Hearing Injury Among U.S. Military Personnel, 2003–2005

IntroductionRates of noise-induced hearing injury (NIHI) among U.S. active duty military have not been previously described using available military medical surveillance data.MethodsNIHI were identified in the Defense Medical Surveillance System (DMSS) using a list of ICD-9-CM diagnosis codes selected in collaboration with military audiologists. To provide a more comprehensive view of the NIHI problem, NIHI-related ICD-9 codes beyond the traditional 388 noise injury–code set were included. Visit rates by gender and age group are reported by quarter, 2003–2005. Overall frequencies and rates by occupational specialty, 2003–2005, are also described.ResultsFrom 2003 to 2005, rates for men were significantly higher than rates for women, with rate ratios (RR) ranging from 1.15 (95% CI =1.07, 1.23) to 1.78 (95% CI= 1.62, 1.93). Rates among women ranged from 2.9 to 6.2 per 1000 person-years; rates among men ranged from 4.5 to 6.7 per 1000 person-years. NIHI rates were highest among those aged ≥40 years and lowest among those aged 17–19 years, with RRs ranging from 3.06 (95% CI=2.77, 3.40) to 5.51 (95% CI=4.88, 6.30) during this time period. Among occupational groups, general officers/executives had the highest NIHI rate over this time period (29.5/1000 person-years), followed by enlisted personnel in training (14.3/1000 person-years) and scientists and professionals (12.8/1000 person-years).ConclusionsWhile data on outpatient injury causes and use of hearing protection are also needed to guide the future design and/or modification of interventions, existing military medical surveillance provides essential information for tracking NIHI and monitoring NIHI intervention effects.