Defining rheumatoid arthritis (RA) flares based on Simplified Disease Activity Index (SDAI) and Clinical Disease Activity Index (CDAI) scores could be highly effective in finding the right treatment for RA, Victoria Konzett, MD, said during her presentation at the ACR Convergence on November 14.

Dr Konzett is a physician researcher and PhD fellow at the Division of Rheumatology of the Medical University of Vienna in Wien, Austria.

CDAI determines severity of RA using clinical data. The SDAI scoring system demonstrates high sensitivity and specificity in predicting a physician's decision to change disease-modifying antirheumatic drug (DMARD) therapy when compared to other scores.

“In times of highly effective treatments available for RA, and consideration of treatment tapering or withdrawal, these definition indices will be useful for guiding decision making in clinical practice and designing clinical trials,” Dr Konzett said.

The investigators analyzed 4256 RA treatment courses from the Norwegian DMARD registry (NOR-DMARD) and 2557 treatment courses from the Vienna RA cohort. The preliminary definitions for absolute changes in SDAI and CDAI for flare are an increase of 4.7 and 4.5, respectively.

When flaring, patients showed worsening in all disease activity core set variables. These patients were also more frequently subjected to subsequent treatment changes. The flares substantially impacted both functional and structural disease outcomes, increasing the Health Assessment Questionnaire score by 2 for flare vs 0.44 for no flare.

In summary, SDAI and CDAI “are easy to apply, pretty straightforward, and are sensitive to change,” Dr Konzett said. “They can be used for all seasons, meaning all purposes in the assessment of RA.”

Reference:
Konzett V. 2480: Definition of rheumatoid arthritis flare based on SDAI and CDAI. Presented at: American College of Rheumatology Convergence. November 14, 2023. San Diego.