Effect of adherence to protocolized targeted intensifications of disease-modifying antirheumatic drugs on treatment outcomes in rheumatoid arthritis: results from an Australian early arthritis cohort

Abstract

Objective: To investigate the association between adherence to treat-to-target (T2T) protocol and disease activity, functional outcomes, and radiographic outcomes in early rheumatoid arthritis (RA). Methods: Data from a longitudinal cohort of patients with early RA were used. Adherence was determined at each followup visit over 3 years according to predefined criteria. The primary endpoint was remission according to Disease Activity Score in 28 joints (DAS28) and Simplified Disease Activity Index (SDAI) criteria. Functional and radiographic outcomes measured by modified Health Assessment Questionnaire and modified total Sharp score, respectively, were secondary endpoints. Results: A total of 198 patients with 3078 clinic visits over 3 years were included in this analysis. After adjusting for relevant variables, although there was no significant association between adherence to T2T and remission rate after 1 year, the associations reached significance after 3 years for both DAS28 (OR 1.71, 95% CI 1.16-2.50; p = 0.006) and SDAI criteria (OR 1.94, 95% CI 1.06-3.56; p = 0.033). After 3 years, adherence was also associated with improvement in physical function (β=0.12, 95% CI 0.06-0.18; p < 0.0001). None of the radiographic outcomes were associated with adherence after either 1 or 3 years, although there was a trend for higher adherence to be associated with less radiographic progression at the end of the study (p = 0.061). Conclusion: Increased adherence to T2T was associated with better longterm disease activity and functional outcomes, which suggests that the benefit of a T2T protocol may be enhanced by ensuring adequate adherence.