2010 Rheumatoid Arthritis Classification Criteria An American College of Rheumatology/European League Against Rheumatism Collaborative Initiative

This criteria set has been approved by the American College of Rheumatology (ACR) Board of Directors and the Euro-pean League Against Rheumatism (EULAR) Executive Committee. This signifies that the criteria set has been quantita-tively validated using patient data, and it has undergone validation based on an external data set. All ACR/EULAR-approved criteria sets are expected to undergo intermittent updates. The American College of Rheumatology is an independent, professional, medical and scientific society which does not guarantee, warrant, or endorse any commercial product or service. Objective. The 1987 American College of Rheuma-tology (ACR; formerly, the American Rheumatism As-sociation) classification criteria for rheumatoid arthri-tis (RA) have been criticized for their lack of sensitivity in early disease. This work was undertaken to develop new classification criteria for RA. Methods. A joint working group from the ACR and the European League Against Rheumatism devel-This article is published simultaneously in the Septembe