Clinical and Epidemiological Characteristics of Patients with Elderly-Onset Rheumatoid Arthritis in Colombia

Objective: This study aims to investigate the prevalence of elderly-onset rheumatoid arthritis (EORA) in Colombia, analyzing demographics, clinical manifestations, laboratory results, and therapeutics characteristics of EORA patients. Furthermore, it compares these with findings observed in patients affected by young-onset rheumatoid arthritis (YORA). Methods: A secondary analysis was conducted using records of all adults diagnosed with rheumatoid arthritis (RA) between 2015 and 2020 reported from 2015-2020 to the High-Cost Account, a division of the Colombian Ministry of Health and Social Protection. Comparative analyses were performed on incident cases to highlight differences between EORA and YORA patients. Results: 195.292 cases were included for prevalence analysis, with 24.933 incident cases for comparative purposes. In 2020, the prevalence of EORA in Colombia increased to 0.12%. Compared to YORA, EORA was more frequently observed in males (p <0.001), with a significantly longer time to diagnosis (p <0,001). There were no differences in disease activity assessed by DAS28 (p = 0.438). At diagnosis, EORA patients were more likely to test negative for anti-CCP (p <0.001), rheumatoid factor (p <0.001), and C-reactive protein (p = 0,005). Moreover, the use of antirheumatic drugs was less frequent among EORA patients. Conclusion: Compared to YORA, EORA patients experience delayed time to diagnosis, less frequent presence of positive auto-antibodies, acute-phase reactants, and reduced use of biological therapy. These findings suggest that EORA may have a less aggressive disease course than YORA.