Treat-to-Target Strategy Achieves High Remission Rates with Sex Differences Attenuated Under Treat-to-Target...

Rheumatoid arthritis (RA) affects women two-three times more frequently than men, and registries report sex-based differences in disease activity and remission. However, sex-stratified outcome data from Saudi Arabia are limited. We evaluated sex differences in disease activity, remission rates, and predictors of remission in the Rheumatoid Arthritis Saudi Database (RASD).

We conducted a prospective cohort study of 647 patients with RA receiving biological or targeted synthetic DMARDs (574 female and 73 male) with at least 12 months of follow-up. Disease activity was assessed using DAS28-CRP, CDAI, FSS, and HAQ-DI across three visits. Remission was defined as DAS28-CRP <2.6. Linear mixed-effects models examined disease activity trajectories by sex, and multivariable logistic regression identified predictors of remission at visit 3. Benjamini-Hochberg correction was applied across six Stage-4 chi-square tests and across three pairwise sex comparisons within each outcome.

Overall remission rates rose from 50.9% at visit 1 to 83.5% at visit 3, with no significant sex differences after correction for multiple comparisons. DAS28-CRP declined significantly over time in both sexes (p <0.001). Males had higher adjusted CDAI at Visit 1 (13.43 vs 11.12; BH-adjusted p = 0.007), but not at visits 2 or 3; the visit-by-sex interaction was significant (unadjusted Type III p = 0.032). Fatigue and functional disability did not differ by sex. ACPA positivity was associated with higher odds of remission (OR 1.67, 95% CI 1.03-2.68, p = 0.036), while RF positivity was associated with lower odds (OR 0.61, 95% CI 0.38-0.96; p = 0.034). Sex was not an independent predictor.

In this Saudi RA cohort, both sexes achieved high remission rates under treat-to-target management, and sex differences in disease activity did not persist after multiple-comparison correction. RF and ACPA, rather than sex, were the dominant predictors of remission.