Objective: The 1987 American College of Rheumatology (ACR) classification criteria for rheumatoid arthritis (RA), previously known as the American Rheumatism Association criteria, have been criticized for not being sensitive enough in the early stages of the disease. This study aimed to develop a new set of classification criteria for RA that addresses this limitation.
Methods: A joint working group representing both the ACR and the European League Against Rheumatism (EULAR) collaborated in a three-phase project to create a novel approach to RA classification. This effort concentrated on identifying factors in patients who were newly diagnosed with undifferentiated inflammatory synovitis. The goal was to distinguish between individuals at high risk and those at low risk for developing persistent and/or erosive disease. This distinction is crucial as it aligns with the contemporary understanding of ‘RA’ as a disease construct.
Results: The newly developed criteria define ‘definite RA’ based on specific factors. Classification requires confirmed synovitis in at least one joint, the exclusion of alternative diagnoses that better explain the synovitis, and a total score of 6 or more (out of a possible 10) from four weighted domains. These domains are: the number and location of affected joints (scoring range 0-5), serological abnormalities (scoring range 0-3), elevated acute-phase response (scoring range 0-1), and the duration of symptoms (two levels; scoring range 0-1).
Conclusion: This revised classification system marks a shift in the current understanding of RA. Instead of focusing on late-stage disease characteristics, it emphasizes features present in the earlier stages that are linked to persistent and/or erosive disease. This new paradigm underscores the critical need for earlier diagnosis and the prompt initiation of effective disease-modifying therapy. Early intervention is essential to prevent or minimize the development of severe consequences, which are currently understood as the typical disease progression within the ‘RA’ construct.
