Upper Extremity Musculoskeletal Injuries in United States Active Duty Service Members: Prevalence/Incidence, Health Care Utilization, and Cost Analysis Spanning Fiscal Years 2016-2021

Introduction: Upper Extremity musculoskeletal injuries (UE MSKIs) represent a major threat to the overall health and readiness of U.S. active duty service members (U.S. ADSMs). However, a lack of prior research and inconsistent study and surveillance methodology has limited Department of Defense (DoD) leaders from assessing and addressing the burden of these conditions. The purpose of this study was to report the incidence, prevalence, and types of UE MSKIs sustained by ADSMs across four branches of service and describe associated health care utilization and private sector costs. Materials and Methods: This was a retrospective, longitudinal population study, including ADSMs from the Air Force, Army, Marine Corps, and Navy. Prevalence and incidence rates for UE MSKIs, associated health care utilization, and private sector costs were obtained by querying electronic health records from military treatment facilities (MTF), private sector care (PC) claims, and theater medical data from the Military Health System Data Repository from October 1, 2015 to September 30, 2021 (Fiscal Years [FYs] 16-21). Utilization associated with UE MSKIs in both the direct care (DC) and PC settings was classified into mutually exclusive outpatient encounter categories and acute inpatient stays. PC costs related to UE MSKIs were captured for each year. Results: In FY21, UE MSKIs occurred in 15.0% of ADSMs (n = 224,842). From FY16-21, the Army had the highest annual prevalence of UE MSKIs (16.7-18.8%), followed by the Air Force (15.2-17.6%), Marine Corps (13.2-14.7%), and Navy (11.1-12.6%). Incidence rate patterns were similar, with the Army sustaining UE MSKIs at 172 to 199 injuries per 1,000 person-years, followed by the Air Force (150-181), Marines (140-157), and Navy (113-130). Overuse/non-specific MSKIs of the shoulder were the most common UE injury type and body region affected, respectively. There were 5,641,191 DC and 1,290,153 PC outpatient encounters from FY16-21 with a primary or secondary diagnosis of UE MSKI. The Air Force was most reliant on PC, with 31.5% of their UE MSKI-related encounters occurring outside MTFs during FY16-21. Conclusions: Among U.S. ADSMs, UE MSKIs are both highly prevalent and financially burdensome. We observed variation across the Services in the prevalence and incidence of UE MSKIs, and their respective reliance on the private sector for management of these conditions. Findings from this work may support military leaders and MSKI researchers who seek to reduce the impact of UE MSKIs on the readiness and overall health of the U.S. Military.