Prevalence and Economic Burden of Osteoarthritis and Rheumatoid Arthritis in the Medically Underserved Rio Grande Valley: A Retrospective Longitudinal Analysis.

Introduction Osteoarthritis and rheumatoid arthritis, two of the most common forms of arthritis worldwide, are chronic diseases affecting the joints. The Rio Grande Valley is characterized by an abundance of health disparities, with previous studies showing increased rates of multiple diseases and disorders in this region. This study aimed to determine both the prevalence and the risk-adjusted average cost of osteoarthritis and rheumatoid arthritis in the Rio Grande Valley and to compare them with the national average. We hypothesize that the prevalence and risk-adjusted average cost of osteoarthritis and rheumatoid arthritis in the Rio Grande Valley will be greater than the corresponding national averages.  Methods Publicly accessible Medicare beneficiary data were utilized for our retrospective longitudinal, observational study. Osteoarthritis and rheumatoid arthritis data for risk-adjusted average total cost, overall prevalence, sex-stratified prevalence, and ethnicity-stratified prevalence, from 2012 to 2022, were compared between the Rio Grande Valley and the national means using specific domains of the "Mapping Medicare Disparities by Population" tool. Independent t-tests and a Mann-Whitney U test compared prevalence rates and risk-adjusted average total cost means, respectively, between the Rio Grande Valley and the national averages.  Results Overall, the prevalence of osteoarthritis and rheumatoid arthritis in the Rio Grande Valley was significantly higher than the national average (39.9% vs. 26.9%, p < 0.001). Women in the region exhibited significantly higher rates of osteoarthritis and rheumatoid arthritis compared to the national average (47.6% vs. 32.1%, p < 0.001), and a similar trend was seen among Hispanic residents (41.6%) compared to the national mean (32.1%) (p < 0.001). Furthermore, the risk-adjusted average total cost for individuals residing in the Rio Grande Valley ($16,084.40) significantly exceeded the risk-adjusted average total cost nationally ($13,073.90) (p < 0.001). Conclusion In the Rio Grande Valley, there is an increased prevalence of osteoarthritis and rheumatoid arthritis compared to the national mean of Medicare beneficiary patients, particularly in women and those of Hispanic heritage. The substantial increase in risk-adjusted average total cost to treat osteoarthritis and rheumatoid arthritis highlights the economic burden faced by residents in the region.