If the ultimate goal of treatment for patients with rheumatoid arthritis is remission, how should remission be evaluated? According to a new study, the Routine Assessment of Patient Index Data 3 (RAPID3) might serve as an alternative because it’s similar to established measures in its predictive ability.
An American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) task force proposed 2 definitions for evaluating remission:
(1) the Boolean-based definition, which requires a swollen joint count (SJC), a tender joint count (TJC), a patient global visual analog scale (VAS) score, and C-reactive protein level (CRP, mg/dL) all ≤ 1.
(2) the Simplified Disease Activity Index (SDAI), based on a composite index of rheumatoid arthritis activity, including SJC, TJC, patient global VAS score, physician global VAS score, and CRP level (mg/dL) ≤ 3.3.
Even with these validated methods for measuring remission, many rheumatologists still do not regularly measure disease activity, possibly because of the added time and expense required to obtain formal joint counts and laboratory assessments.
RAPID3 might be a good option because it requires only patient input and can be completed quickly, hypothesized researchers led by Muznay N. Khawaja, MD, of Mercy Catholic Medical Center in Darby, Pennsylvania. They evaluated the performance of RAPID3, with and without minimal joint count, versus the Boolean and SDAI remission definitions in the current study, writing in Arthritis Care & Research.
The study used data from the Tocilizumab Safety and the Prevention of Structural Joint Damage (LITHE) study, a 2-year, double-blind, phase III study of tocilizumab in patients with moderate to severe rheumatoid arthritis who had inadequate responses to methotrexate therapy. Patients were randomly assigned to receive intravenous placebo and methotrexate, 4 mg/kg tocilizumab and methotrexate, or 8 mg/kg tocilizumab and methotrexate, and were excluded if they had serious concomitant diseases; 690 patients had sufficient data at the end of year 2 to be included in this analysis.
This study was funded by F. Hoffman-La Roche (Roche). The sponsor and all authors were involved in the study design; collection, analysis, and interpretation of data; writing of the manuscript; and decision to submit the manuscript for publication.
Muznay N. Khawaja, Martin J. Bergman, Jeffrey Yourish, et al. “Routine Assessment of Patient Index Data 3 and the American College of Rheumatology/European League Against Rheumatism Provisional Remission Definitions as Predictors of Radiographic Outcome in a Rheumatoid Arthritis Clinical Trial With Tocilizumab.” Arthritis Care Res (Hoboken). 2017 May;69:609-615. doi: 10.1002/acr.23008. Epub 2017 Apr 7.
Joshua F. Baker and Michael D. George. “Letter to the Editor: Is RAPID3 a good predictor of radiographic outcomes in rheumatoid arthritis? Comment on article by Khawaja et al.” Arthritis Care Res (Hoboken). 2017 Jun 26. doi: 10.1002/acr.23306. [Epub ahead of print]
Martin J. Bergman, “Letter to the Editor: Is RAPID3 a Good Predictor of Radiographic Outcomes in Rheumatoid Arthritis? Reply to Letter to the Editor in Comment on the Article by Khawaja et al.” Arthritis Care Res (Hoboken). 2017 Jun 26. doi: 10.1002/acr.23307. [Epub ahead of print]