Little is known about possible predictors of long-term survival on biologic disease-modifying antirheumatic drugs (bDMARD) after achievement of deep clinical remission in rheumatoid arthritis (RA) patients. We aimed at assessing factors associated with drug persistence of the first bDMARD in RA patients who achieved Simplified Disease Activity Index (SDAI) remission.
The clinical charts of RA patients beginning a first bDMARD were retrospectively reviewed, and those who achieved SDAI-based remission were selected for this analysis. Drug retention rate and mean survival time (MST) were estimated using Kaplan-Meier curves, and hazard ratios (HRs) of discontinuing bDMARD were estimated by multivariate Cox-regression models.
Eight-six patients were on SDAI remission, and the survival rate of bDMARDs since 'baseline-time' was 82.6% (MST = 77.8 (95% CI: 69-86) months). Once on remission, patients not taking concomitant glucocorticoids had significantly higher survival rate (90.7%, MST = 86.3 (95% CI: 78-95) months) than patients who continued to intake low dose of glucocorticoids (68.8%, MST = 56.9 (95% CI: 45-69) months; P = .008). On the contrary, those patients assuming methotrexate (MTX) had significantly higher survival (87.7% (MST = 81.8 (95% CI: 73-91) months) than patients who were not taking MTX (66.7% (MST = 55.3 (95% CI: 40-71) months) (log-rank 4.72, P = .03). After the achievement of disease remission, stopping glucocorticoids (HR 0.31, 95% CI: 0.10-0.93) and methotrexate co-therapy (HR 0.34, 95% CI: 0.12-0.98) were independently associated with a lower risk of bDMARD discontinuation.
Among RA patients on clinical remission with a first bDMARD, those stopping glucocorticoids and continuing MTX had much longer survival on bDMARD.