To compare achievement of remission in two early rheumatoid arthritis (RA) treat-to-target (TTT) cohorts, one tight control cohort targeting stringent remission in a randomized controlled strategy trial and one observational cohort targeting a looser definition of remission in clinical practice.
We analyzed data from the ARCTIC trial and the NOR-VEAC observational study. Both were Norwegian multicenter studies including disease modifying anti-rheumatic drug (DMARD)-naïve RA-patients and implementing TTT. The target in ARCTIC was remission defined as a Disease Activity Score (DAS44) <1.6 plus 0 of 44 swollen joint count, while the target in NOR-VEAC was the less stringent remission of DAS28<2.6. We assessed achievement of the study-specific targets and compared achievement of the ACR/ EULAR Boolean remission during two years of follow-up.
We included 189 patients from ARCTIC and 330 patients from NOR-VEAC. More than half in each cohort had reached the study-specific target at 6 months, increasing to more than 60% at 12 and 24 months. The odds of reaching ACR/EULAR Boolean remission during follow-up were higher in ARCTIC than in NOR-VEAC, with statistically significant differences at 3 months (OR 1.73; 95% CI 1.03-2.89), 12 months (OR 1.97; 95% CI 1.21-3.20) and 24 months (OR 1.82; 95% CI 1.05 - 3.16).
A majority of patients in both cohorts reached the study-specific treatment targets. More patients in ARCTIC than in NOR-VEAC achieved ACR/EULAR Boolean remission during follow-up, suggesting that targeting a more stringent definition of remission provide further potential for favorable outcomes of a TTT strategy.