Musculoskeletal Injuries in Female U.S. Active Duty Service Members: Prevalence/Incidence, Health Care Utilization, and Cost Analysis Spanning Fiscal Years 2016-2021.

Introduction: Musculoskeletal injuries (MSKIs) are highly prevalent and costly conditions among active duty service members (ADSMs), and female service members sustain these injuries at a higher rate than men. However, lack of women-specific research regarding MSKIs in the U.S. military has limited Department of Defense (DoD) leadership from assessing and addressing the burden of these conditions. The purposes of this study were to report the incidence, prevalence, and types of MSKIs sustained by female ADSMs across the four services in direct care (DC) and private sector care (PC) settings from fiscal years (FYs) 2016 through 2021 and to quantify and describe the health care utilization and private sector costs associated with MSKIs in women over the same period.

Materials and methods: This retrospective, longitudinal population study included ADSMs from the Air Force, Army, Marine Corps, and Navy. Prevalence and incidence rates for Head/Neck, Upper Extremity (UE), Spine, and Lower Extremity (LE) MSKIs in female ADSMs, associated health care utilization, and private sector costs were derived by querying electronic health records from military treatment facilities, PC claims, and theater medical data from the Military Health System Data Repository from October 1, 2015 to September 30, 2021 (FY16-21). Health care utilization associated with MSKIs among female ADSMs for each body region in DC and PC settings was classified into mutually exclusive outpatient encounter categories and acute inpatient stays. PC MSKI-associated costs in service women were captured for each year and categorized by service, body region, and setting.

Results: In FY21, 10.8% (n = 27,976) of female ADSMs sustained Head/Neck MSKI, 16.3% (n = 42,294) UE MSKI, 23.6% (n = 61,048) Spine MSKI, and 33.3% (n = 86,235) LE MSKI. Across the study period, female ADSMs had a 25%-29% higher risk of any MSKI (risk ratio (RR) 1.25-1.29) relative to men. Female soldiers had the highest annual prevalence of MSKIs (62.1%-66.4%), while female Marines had the highest risk of MSKI relative to men (RR 1.40-1.47) for all four major body regions. From FY16 to FY21, the body region with the highest risk of MSKI relative to men was Head/Neck (RR 1.61-1.63), while the region with the lowest relative risk was UE (RR 1.05-1.10). LE MSKIs represented the most common and costly type of injury in female ADSMs, with 406,997 outpatient DC and 87,374 PC encounters in FY21. Total PC costs of LE MSKI for female ADSMs were $30,643,535 in FY21 alone.

Conclusions: This is the first population-level assessment of MSKI prevalence, incidence rates, health care utilization, and PC costs over a 6-year period for service women in the military health system (MHS). Female ADSMs sustain MSKIs at a higher rate than their male counterparts. Given the critical role of service women in the military, MHS leaders, researchers, and public health officials should continue to explore the underlying causes of these disparities in MSKI rates between the sexes, by expanding research efforts to all services and military settings.