Osteoarthritis Across Joint Sites in the Million Veteran Program Cohort: Insights from Electronic Health Records and Military Service History

OBJECTIVE:To characterize the relationship between the frequency of idiopathic osteoarthritis (OA) and characteristics including demographics, comorbidities, military service history, and physical health in a veteran population. METHODS:We performed a cohort study in the Million Veteran Program (MVP) using International Classification of Diseases, 9th and 10th revision codes to define the frequency of site-specific OA across 3 joints or unspecified OA in veterans with respect to demographics (eg, age, sex, race and ethnicity), military service data, detailed electronic health records, military branch, and war era. RESULTS:We validated previous reports of sex- and age-dependent differences in OA frequency, and we identified that unspecified OA was associated with a higher frequency of 16 Deyo-Charlson comorbidities. These associations generally persisted within each isolated joint site-specific OA. Depending on military branch, prior military engagement was differentially associated with the frequency of OA. Prior United States Army and Navy service were associated with higher and lower risk, respectively, of OA across all joint sites; however, multivariable-adjusted models adjusting for a range of covariates, including age, sex, and ancestry, reversed the apparent protective effect of prior Navy service. CONCLUSION:These findings highlight the breadth of factors associated with OA in the MVP veteran population and suggest that physical status may be a modifiable risk factor for OA. This work may help in the design of strategies to optimize appropriate detection, intervention, treatment, and even rehabilitation for OA in veterans and the general population.