A survey on the medication adherence to methotrexate among rheumatoid arthritis patients treated with self-administered biologic drugs.

ABSTRACT

OBJECTIVES: Methotrexate (MTX) is the most widely used co-therapy among rheumatoid arthritis (RA) patients using biological disease-modifying anti-rheumatic drugs (bDMARDs). However, adherence to MTX treatment remains a concern with estimates of adherence ranging from 59 to 63%. The objective of this study was to assess the self-reported use and adherence to MTX among RA patients treated with self-administered bDMARDs. METHODS: An electronic questionnaire survey was conducted in 68 community pharmacies in Finland. To be included in the present study patients had to be at least 18 years old, be currently using a self-administered bDMARD and be diagnosed with RA. The results are presented as medians with their respective interquartile ranges (IQR) or percentages. RESULTS: Of the 158 pharmacy customers asked to participate, 135 (85%) consented to complete the questionnaire. The included respondents were predominantly female (72%) with a median age of 55 (IQR 44-65) and rheumatic activity of 3 out of 10 (IQR 2-6.5). The majority (91%) of the included respondents were using TNF-inhibitors and 27% of all patients were on biologic monotherapy. MTX was currently used by 45% of the respondents while 50% were past users. Of the current MTX users, 6.8% identified themselves moderately non-adherent to the treatment. MTX-related adverse events were important factors associated with nonadherence and discontinuation of the treatment. CONCLUSIONS: Only 45% of the respondents were currently using MTX co-therapy, but the ones who did were adherent to their treatment. Self-reported adherence may however be subject to social desirability bias and recall bias.