Abstract
Objective The objective of this study was to determine the prevalence and clinical characteristics of spondyloarthritis (SpA) in Alaska Native and American Indian (AN/AI) peoples of Alaska.
Methods We queried electronic health records from participating tribal health organizations within the Alaska Tribal Health System from 2012 to 2019 to identify adults with a potential diagnosis of SpA based on International Classification of Diseases, 9th or 10th revision codes. Medical records were abstracted to confirm the diagnosis and clinical characteristics. Adults who were alive at the end of the study period and had a confirmed clinician diagnosis of SpA were included in prevalence calculations. We determined whether included adults had medical record documentation of meeting SpA classification criteria.
Results The age-adjusted prevalence of any form of SpA was 355 per 100,000 adults (95% CI 317-397); for psoriatic arthritis it was 162 (95% CI 137-191), and for ankylosing spondylitis it was 107 (95% CI 86-131). Two-thirds (67%) of adults with any form of SpA who were tested were HLA-B27 positive. Two-thirds of adults with SpA other than psoriatic arthritis (69.1%) had documentation in their medical record to confirm that they met clinical classification criteria for axial SpA.
Conclusion The prevalence of SpA in AN/AI peoples of Alaska is lower than previously reported in this population but is higher than in most populations previously studied. Understanding the increased prevalence of SpA in this population may help clinicians identify and treat the condition in AN/AI peoples.
PLAIN LANGUAGE SUMMARY
Spondyloarthritis (SpA) is an inflammatory joint disease of the spine, limbs, hands, and feet. There are several types of SpA that describe different patterns of joint involvement and other disease features. This study describes the prevalence of multiple types of SpA in the Alaska Native and American Indian (AN/AI) peoples of Alaska. We reviewed charts of adults diagnosed with SpA within the Alaska Tribal Health System to understand how common SpA is in this population and what features people with SpA have. Whereas the prevalence of SpA is higher in AN/AI peoples than in other populations previously studied, it is slightly lower than in previous studies done in this population. The most common form of SpA was psoriatic arthritis, followed by ankylosing spondylitis, undifferentiated SpA, then reactive arthritis. Understanding how common SpA is in this population could help more people reach a diagnosis and receive treatment.
- Accepted for publication March 15, 2026.
- Copyright © 2026 by the Journal of Rheumatology
