Self-reported Adherence to Treatment and Disease Activity in Patients with Rheumatoid Arthritis from Iran; Based on RHEUMATRY-RA Registry: A Cross-sectional Study

Background: Poor medication adherence challenges efficacy and costs in achieving treatment goals for rheumatoid arthritis (RA). This study aimed to determine the prevalence of treatment adherence and its related factors in Iranian RA patients. Methods: This cross-sectional study included RA outpatients referred to the rheumatology clinic of Shariati Hospital between March 2017 and September 2018, with the diagnosis based on the American College of Rheumatology (2010 ACR/EULAR) criteria. Treatment adherence was evaluated using the standardized Persian version of the 8-item Morisky Medication Adherence Scale (MMAS-8). Demographic and clinical information was extracted through the Iranian RA registry system (RHEUMATRY-RA). Results: Of 275 participants (222(81%) female), 20(7%) patients had active RA. Medication adherence was low in 138(50%) of patients, moderate in 81(30%) and high in 56(20%). In patients with disease duration ≤ 10 years, medication adherence was significantly associated with sex and occupation. It was observed that older patients (adjusted odds ratio (aOR) (95% confidence interval (CI): 1.01(0.98, 1.03)) and women (aOR (95% CI): 1.64(0.60, 4.45)) had more adherence. Patients on glucocorticoids demonstrated higher (aOR (95% CI): 1.76(0.81, 3.84)) and on methotrexate lower (aOR (95% CI): 0.58(0.18, 1.86)) adherence. The odds of disease activity were 21% lower in people who had adhered to medication (aOR (95% CI): 0.79(0.29, 2.15)). Conclusion: Despite the inherent complexity of adherence behaviors, this study identified a high prevalence of poor medication adherence among RA patients. Patients with better adherence may have lower disease activity, underscoring its role in effective disease management.