Chinese registry of rheumatoid arthritis (CREDIT): III. The transition of disease activity during follow-ups and predictors of achieving treatment target.

Aim: The Chinese Registry of Rheumatoid Arthritis (CREDIT) is the first nationwide multi-center prospective rheumatoid arthritis (RA) registration cohort in China. This study aimed at presenting disease activities transition during follow-ups and identifying predictors to treatment response.

Method: Patients who had baseline, 3- and 6-month follow-up data from November 2016 to April 2018 were recruited. Then, we selected patients who did not reach remission (REM)/low disease activity (LDA) at baseline to investigate the predictors for treatment response.

Results: There were 979 patients included (83.00% female, mean age 51.8 and median duration 3.84 years). REM/LDA rate at baseline, 3-, and 6-month follow-up were 34.02%, 59.35% and 68.23%. Additionally, early RA has more chance to achieve targets than established RA (6 months: 59.79% vs 48.13%, P = .002). High baseline Disease Activity Score of 28 joints (DAS28) (early RA: odds ratio [OR] 1.319, P = .019; established RA: OR 1.337, P < .001), biologic disease-modifying anti-rheumatic drugs (bDMARD)/targeted synthetic DMARD combined conventional DMARD therapy (early RA: OR 9.023, P = .046) and prednisolone usage (early RA: OR 2.526, P < .001) are positively associated with Clinical Disease Assessment Index (CDAI) decreasing at 3 months. Low baseline DAS28 (REM/LDA: early RA: OR 0.650, P < .001; established RA: OR 0.612, P < .001. REM: early RA: OR 0.743, P = .021; established RA: OR 0.674, P < .001), young age (REM: early RA: OR 0.977, P = .048) and decrease of CDAI at 3 months (REM/LDA: early RA: OR 7.185, P < .001; established RA: OR 8.752, P < .001. REM: early RA: OR 5.602, P < .001; established RA: OR 4.955, P < .001) predict REM/LDA at 6 months.

Conclusion: Disease activity decreased during follow-ups. Disease duration, baseline disease activity, age, treatment strategies, and CDAI decreasing were associated with treatment response.