Prevalence and Associated Factors for Non-adherence in Patients with Rheumatoid Arthritis

Objective. To estimate the prevalence of non-adherence to rheumatoid arthritis (RA) medication and identify the associated factors for non-adherence in RA patients. Methods. Among the KORean Observational study Network for Arthritis 3,523 patients who completed a questionnaire about the adherence to RA medication were analyzed. The patients were divided into two groups: 1) adherent group, patients who skipped medication <= 5 days within the past 2 months; and 2) non-adherent group, patients who skipped >= 6 days of medication. The baseline characteristics were compared, and multivariable regression analysis was performed to identify the associated factors for non-adherence. Results. The non-adherent group had 339 patients (9.6%). The common causes of non-adherence were forgetfulness (45.8%), absence of RA symptoms (24.7%), and discomfort with RA medication (13.1%). Younger age (odds ratio [OR] 1.02, p<0.01) and higher income (OR 1.70, p<0.01) were associated with an increased risk of non-adherence. Whereas higher functional disability (OR 0.68, p<0.01) and oral corticosteroid use (OR 0.73, p=0.02) were associated with a decreased risk of non-adherence. The associated factors differed according to cause of non-adherence. Having adverse events (OR 2.65, p=0.02) was associated with the risk of non-adherence due to discomfort with RA medication while a higher level of education (OR 2.37, p=0.03) was associated with the risk of non-adherence due to an absence of RA symptoms. Conclusion. The 9.6% of Korean RA patients were non-adherent to RA medication. The associated factors differed according to the cause of non-adherence. Therefore, an individualized approach will be needed to improve the adherence to RA medication.