Prevalence of Rheumatoid Arthritis, Osteoarthritis and Gout among Alaska Native/American Indian Peoples in Alaska

OBJECTIVE: The objective of this study was to determine the prevalence of three common forms of arthritis (rheumatoid arthritis, osteoarthritis, and gout) in Alaska Native and American Indian (AN/AI) peoples of Alaska. METHODS: We identified adults with a potential diagnosis of rheumatoid arthritis, osteoarthritis, or gout based on queries of the electronic health records within participating organizations in the Alaska Tribal Health System based on ICD-9 and ICD-10 codes. We performed medical record abstraction for a subset of individuals with potential arthritis to confirm the diagnosis, classification criteria documented in the medical record, and associated clinical features. We applied the validation results to the full sample of adults with potential arthritis identified from electronic health record queries to estimate the point prevalence of each form of arthritis as of December 31, 2019. RESULTS: Of the three types of arthritis, osteoarthritis was the most common (overall age-adjusted prevalence 14.0% (95% CI 13.2-14.8%)), followed by rheumatoid arthritis (overall age-adjusted prevalence 2.39% (95% CI 2.19-2.60%)), then gout (overall age-adjusted prevalence 1.33% (95% CI 1.20-1.47%)). Osteoarthritis and rheumatoid arthritis were more common in women than men, while gout was more common in men than women. The prevalence of all three types of arthritis increased with age. CONCLUSION: Compared to U.S. or global population-based studies, the prevalence of osteoarthritis in AN/AI peoples of Alaska is similar, while the prevalence of gout is lower than expected and the prevalence of rheumatoid arthritis is high and similar to prior studies in this population.