To assess the association of demographic and clinical factors with the clinical decision of tapering biologic disease modifying antirheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA) in daily practice.
All RA patients receiving bDMARDs were documented by 14 rheumatologists when presenting in 9 specialized private practices. Statistical analyses employed multivariable logistic models for dose reduction with the covariates age, gender, disease duration until bDMARD start, smoking status, disease activity, comorbidity, functional capacity, radiographic damage, concomitant methotrexate (MTX) treatment, rheumatoid factor positivity, and glucocorticoid use. In the multivariable model (MVM), missing values were imputed.
Data of 586 RA patients on bDMARD treatment were available, 171 of which (29%) received a reduced dose. The highest rates of patients with dose reduction were seen for rituximab (67%) and infliximab (50%). The degree of dose reduction was most prominent for rituximab (57%). In the MVM, 6/11 covariates were significantly associated with dose reduction: age (odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.05; P = 0.002), time between disease onset and bDMARD start (OR 1.03, 95% CI 1.01-1.06; P = 0.015), DAS 28 < 2.6 (OR 1.55, 95% CI 1.01-2.37; P = 0.045), MTX therapy (OR 1.52, 95% CI 1.03-2.25; P = 0.036), comorbidity (OR 1.20, 95% CI 1.01-1.42; P = 0.036), and glucocorticoid dose (OR 0.82, 95% CI 0.76-0.89; P < 0.001).
DAS 28 remission, concomitant MTX, and lower glucocorticoid doses were positively associated with dose tapering of bDMARDs in RA patients. While this could be expected, the reason for the association with age, comorbidity, and the time between disease onset and bDMARD start is less clear. Key points • In rheumatology practice, tapering of biologic disease modifying antirheumatic drugs is feasible in nearly 30% of patients with rheumatoid arthritis. • The degree of dose reduction may exceed 50% of the recommended dose. • In a multivariable model, concomitant methotrexate is positively associated with dose tapering of biologic disease modifying antirheumatic drugs.