Background and objective: Poor medication adherence is an obstacle for treatment outcome. There are many studies of interventions for promoting adherence. This study aimed to assess the impact of patient education on medication adherence in rheumatoid arthritis (RA) patients and to identify factors associated with adherence.

Methods: A randomized controlled, single-blinded was performed. One hundred and seventy-six patients who were diagnosed of RA by 2010 ACR/EULAR classification criteria were enrolled. Fifty-six patients with good adherence, defined as medication taking behavior questionnaire for Thai patient (MTB) > 23 or pill count > 80% in a previous month, were excluded. One hundred and twenty patients were randomized by block randomization into intervention group and control group. Intervention group received a 30-minute directed counseling and a disease brochure. Control group received only a disease brochure. The primary outcomes were adherence rate measured by pill count and MTB score improvement after 12 weeks. 

Results:  Adherence rate increased significantly from baseline in both study groups, however, the improvement in the intervention group was significantly greater than in the control group (5.38 ± 12.90 vs. 3.18 ± 14.23, p = 0.023). MTB score improved in intervention group (1.12 ± 2.22, p < 0.001); but not in control group (0.44 ± 2.92, p = 0.251). DAS28 and EQ-5D were unchanged from baseline in both groups. Multivariate regression found cognitive impairment (β = 0.97, 95%CI 0.37-1.56, p = 0.002), illness perception (β = 1.39, 95%CI 0.39-2.39, p = 0.007), quality of life (β = 23.20, 95%CI 4.2342.06, p = 0.016), and anxiety (β = 1.02, 95%CI 0.17-1.87, p = 0.019) were independently associated with baseline adherence.

Conclusions: In 12-week period, directed counseling significantly increased adherence. However, the impact of adherence on disease activity and quality of life may need a longer-term study. Several factors associated with baseline adherence were identified including cognitive Impairment, illness perception, quality of life, and anxiety.