Assessment of the adherence to disease-modifying drugs in patients with chronic inflammatory rheumatic diseases: Results of a survey of 1594 patients

Objectives: a) to describe the self-reported adherence to disease modifying drugs (DMARDs) (methotrexate and biological DMARDs) among patients with chronic inflammatory rheumatic diseases (CIRDs); b) to assess factors associated with non-adherence.

Methods: An observational, cross-sectional, nationwide study was conducted through the use of an electronic survey, which was released via patient organizations in France to rheumatic patients. The main outcome was the rate of non-adherence to DMARDs, which was evaluated with the following question "Have you ever tried to stop or space out your treatment in contrast to what was planned with your doctor?" A positive answer was considered "low adherent". Sociodemographic variables, type of CIRD and treatment information were also collected. Factors associated with low adherence to methotrexate and bDMARDs were explored by univariate and multivariate logistic regressions.

Results: Among the 1594 participants who completed the survey, 795 (49.9%) were receiving methotrexate and 709 (44.5%) bDMARDs. A total of 159 (20.0%) were identified as low adherents to methotrexate, and being a woman was independently associated with low adherence (OR 1.90 [95% CI 1.07 - 3.36)] to this drug. Regarding bDMARDs, 177 (25.0%) were identified as low adherent, and the factors independently associated with low adherence were being employed (OR 1.47 [95% CI 1.04 - 2.09]) and no concomitant use of methotrexate (OR 0.51 [95% CI 0.36 - 0.73]).

Conclusions: This study suggests that more than 20% of CIRDs patients are low adherent to their DMARDs, and this is more frequent when bDMARDs are administered as a monotherapy.