To analyze the efficacy of tocilizumab (TCZ) and the factors that influence achievement of Boolean-based remission in patients with rheumatoid arthritis (RA) treated with TCZ in daily clinical practice.
The efficacy of TCZ at 24 weeks after initiation of TCZ in 80 patients with RA was analyzed by comparing achievement of "DAS28 remission" with that of "Boolean-based remission". The predictive factors that influence achievement of Boolean-based remission were determined using multiple logistic regression analysis using a step-wise method.
DAS28 remission and Boolean-based remission were achieved in 50.0 and 12.5% of patients, respectively. Significant differences in achieving Boolean-based remission were observed when patients were stratified by disease duration in tertiles (p < 0.05) and by physical function in tertiles (p < 0.05); no such differences were observed for achieving DAS28 remission. The least achievable component among the Boolean-based remission criteria was patient's global assessment. The predictive factor for not achieving Boolean-based remission at 24 weeks was having a worse baseline physical function (odds ratio, 3.66; 95 % confidence interval, 1.17-14.48).
This study suggests that baseline disability predicts a lack of achievement of Boolean-based remission. Thus, better responses to TCZ may be obtained when TCZ is initiated in RA patients before disability develops.