Definition of rheumatoid arthritis flare based on SDAI and CDAI

Abstract

ObjectiveTo develop and validate definitions for disease flares in rheumatoid arthritis (RA) based on the quantitative Simplified and Clinical Disease Activity Indices (SDAI, CDAI).MethodsWe analysed RA treatment courses from the Norwegian disease-modifying antirheumatic drug registry (NOR-DMARD) and the Vienna RA cohort. In a receiver operating curve analysis, we determined flare definitions for absolute changes in SDAI and CDAI based on a semiquantitative patient anchor. NOR-DMARD was sampled into an 80%-training cohort for cut point derivation and a 20%-test cohort for internal validation. The definitions were then externally validated in the independent Vienna RA cohort and tested regarding their performance on longitudinal, content, face, and construct validity.ResultsWe analysed 4256 treatment courses from NOR-DMARD and 2557 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. The definitions performed well in the test and external validation cohorts, and showed clinical face and construct validity, as flares significantly impact both functional (∆Health Assessment Questionnaire flare vs no-flare +0.43; p<0.001) and structural (∆modified Sharp Score 43% higher after flare; p<0.001) disease outcomes, and reflect consistent worsening across all disease core sets, both patient reported and objective.ConclusionWe here provide novel definitions for flare in RA based on SDAI and CDAI, validated in two large independent real-world cohorts. In times of highly effective medications for RA, and consideration of their tapering, these definitions will be useful for guiding decision making in clinical practice and designing clinical trials.

COVID-19 Impact on Patients with Immune-Mediated Rheumatic Disease: A Comparative Study of Disease Activity and Psychological Well-Being Over Six Months

“… Rheumatoid arthritis: worsening of symptoms compared to the pre-COVID-19 state plus an increase of 4.5 points in the CDAI and/or need to change treatment (7). Systemic Lupus Erythematosus: worsening of symptoms compared to the pre-COVID-19 state plus an increase at least 4 points in the SLEDAI and/or need to change treatment (8).…”

“…-Rheumatoid arthritis: worsening of symptoms compared to the pre-COVID-19 state plus an increase of 4.5 points in the CDAI and/or need to change treatment (7).…”

Long-term sustainability of response to upadacitinib among patients with active rheumatoid arthritis refractory to biological treatments: results up to 5 years from SELECT-BEYOND

“…Reasons for loss of response were summarised and included those who discontinued upadacitinib due to lack of efficacy and those who remained on upadacitinib but never recaptured response by the cut-off date after having lost response at two consecutive visits. CDAI changes of 2 units (>2 CDAI) and 4.5 units (≥4.5) were assessed as different thresholds for minimal clinically important differences (MCID) for worsening of RA (as reported by Curtis et al 24 and Konzett et al 25 ) among those who initially achieved a response but later lost it. The Kaplan-Meier method was also used to evaluate the sustainability of response in the subgroup of patients with an IR or intolerance to TNF inhibitors (TNF-IR).…”

Validation of the definition of rheumatoid arthritis flare based on SDAI and CDAI in clinical practice in two French independent cohorts

“…New definitions for flares in rheumatoid arthritis (RA) based on the Simplified and Clinical Disease Activity Indices (SDAI, CDAI) have been recently introduced 1. In this article, the authors defined flare as an absolute increase of 4.7 in SDAI and 4.5 in CDAI.…”