Rheumatoid Arthritis Flare Threshold Is Determined

A cut-off value for identifying a rheumatoid arthritis (RA) flare has been determined by using the Tocilizumab SubCutAneous (TOSCA) study results.

A group of French researchers set out to establish a threshold for identifying an RA flare with the Flare Assessment in RA (FLARE-RA) questionnaire. This self-administered instrument is used to identify patients who have had an RA flare between 2 office visits.

To do so, they analyzed RA disease activity during the TOSCA study assessed with the FLARE-RA questionnaire and the Disease Activity Score for 28 Joints with Erythrocyte Sedimentation Rate (DAS28ESR). They then determined whether a correlation existed between the FLARE-RA score at week 12 and week 24 and the area under the receiver operating characteristic curve (ROC AUC) for the monthly DAS28ESR.

In addition, they used patient satisfaction assessed with the Patient Acceptable Symptom State (PASS) instrument at baseline and at week 24 as a surrogate marker for absence of flare. Then they used an ROC curve to determine the optimal FLARE‑RA score cutoff value, below which patient satisfaction reached a PASS score that reflected an absence of flare.

As a result, they found a moderate correlation between the FLARE-RA score and the DAS28ESR; ρ was 0.4 at week 12 (P < .0001) and 0.5 at week 24 (P < .0001). Based on PASS results, the optimal cutoff for identifying the absence of flare was determined to be a FLARE-RA score of 2.3 with an AUC of 0.8.

The researchers concluded that because “FLARE-RA and DAS28ESR assessments differ; we propose a FLARE-RA cut-off of 2.3, below which the situation (ie, without flare) is acceptable for patients.”

—Ellen Kurek

Reference:

Aouad K, Gaudin P, Vittecoq O. et al. Cut-off value to identify a flare using the Flare Assessment in Rheumatoid Arthritis (FLARE-RA) questionnaire: analysis of the TOSCA study. Rheumatology. 2022;61(1):337-344. doi:10.1093/rheumatology/keab261