Capturing and Categorizing the Burden of Musculoskeletal Injuries in U.S. Active Duty Service Members: A Comprehensive Methodology

Background: Musculoskeletal injuries (MSKIs) represent the most common, costly, and impactful medical conditions affecting active duty service members (ADSMs) of the United States Armed Forces. Inconsistent, variable MSKI surveillance methods and often incompletely described criteria for cohort selection, injuries, incidence, and prevalence have limited efforts to observe longitudinal trends, identify gaps in care, or highlight specific military branches or sites that could benefit from enhanced MSKI intervention protocols. The purpose of this manuscript is to present a comprehensive, well-documented, and reproducible framework for capturing and categorizing MSKI burden, healthcare utilization, and private sector costs for ADSMs across a 12-year period spanning the International Classification of Diseases, 10th Revision, Clinical Modification transition. Methods: This was a retrospective, longitudinal population study, including ADSMs from the Air Force, Army, Marine Corps, and Navy. Prevalence and incidence rates for Upper Extremity, Lower Extremity, Spine, and Head/Neck MSKIs, associated health care utilization, and private sector costs were obtained by querying electronic health records from military treatment facilities, private sector care (PC) claims, and theater medical data from October 1, 2010 to September 30, 2021 (Fiscal Years 10-21), using the Military Health System Data Repository. Utilization associated with MSKIs per body region in the direct care and PC settings was classified into mutually exclusive outpatient encounter categories and acute inpatient stays. PC MSKI-associated costs were captured per year and categorized by service, body region, and setting. Conclusions: MSKI surveillance research in ADSMs has been impacted by variable, often incompletely described methods. While our approach is not without limitations, our aim was to present a well-documented, reproducible methodology for MSKI investigation in military personnel. By presenting a comprehensive blueprint for capturing and categorizing MSKI care in U.S. service members, our goal is for this methodology to enhance the efforts of researchers, public health officials, and Military Health System leaders to combat MSKIs, the primary medical threat to military readiness.