All ACR-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.Publication HistoryIssue published online: 31 MAY 2006Article first published online: 31 MAY 2006Manuscript Accepted: 17 FEB 2006Manuscript