Background/Purpose: While weekly methotrexate (MTX) remains the gold standard treatment for patients with RA, studies suggest that MTX adherence may be sub-optimal and could be associated with side effects, poor outcomes, and unnecessary switching to other DMARDs. We set out to assess MTX adherence in patients with RA using electronic medication monitoring in a real-world non-clinical setting.

Methods: Patients were participants in the National Data Bank for Rheumatic Diseases (NDB) longitudinal survey-based study that reported oral MTX initiation independent of other treatments within a year of September 2016. Study patients used a Medication Event Monitoring System (MEMS®) to accurately record when they accessed their MTX pills and completed the Beliefs about Medications Questionnaire (BMQ). The BMQ assesses “General” beliefs about medications and also those taken for a “Specific” condition (RA). While validated in several chronic disease, the BMQ has never been studied in RA. After 24 weeks the MEMS data were retrieved and baseline patient characteristics were summarized by categorical adherence level.

Results: Of the 119 eligible patients invited, 62 enrolled and 32 had completed the study by May 2017. Mean (SD) MTX experience at the first time of MEMS use was 7.4 (5.0) months. Nine (28%) patients had perfect adherence, 7 (22%) had 1 interrupted week, 8 (25%) had ≥2 interrupted weeks, and 8 (25%) had major adherence deviations, including treatment discontinuation. On average, 80% of dosing intervals were between 6 and 8 days and MTX dose was taken in 77% of the monitored weeks. The table compares baseline characteristics between adherence categories. There was a significant difference in Non-Hispanic Caucasian and BMQ-General-Overuse response between patients with ≤1 interrupted weeks and ≥2 (94 vs. 63%, p=0.03 and 11.1 vs. 9.4, p=0.02, respectively). There were also clinically significant differences in functional assessment (HAQ-II 0.7 vs. 1.2) and fatigue (VAS 2.9 vs. 4.9).

Conclusion: This study demonstrated the feasibility of using remote electronic medication monitoring in a participatory US RA population; yet, even with such participation biases, half had important adherence interruptions with MTX. Patients with beliefs that medicines are overused by doctors were most likely to be adherent while Non-Caucasian race and worse function and fatigue were less likely. Next steps include a larger and longer follow-up and investigating early intervention to improve MTX adherence.

Reference: Horne, R (2000) Assessing perceptions of medication: psychological perspectives In Handbook of Drug Research Methodology Publ UK Drug Utilization Research Group ISBN 0 9537011 07

Table. Baseline characteristics of RA patients by 24-week MTX adherence (≤1 vs ≥2 interrupted weeks)

ACR Meeting Abstracts - https://acrabstracts.org/abstract/real-world-oral-methotrexate-adherence-measured-electronically-in-patients-with-established-rheumatoid-arthritis/