Hi . I want to provide a little clarification on the American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) classification criteria. Different aspects/criteria of the examination and diagnostic process do have different weights. You can find the criteria laid out and discussed in this article, as well as the previous criteria, so one can see what was changed and why: https://www.uptodate.com/contents/diagnosis-and-differential-diagnosis-of-rheumatoid-arthritis/print#H16. However, I want to post for you and everyone out there the criteria for easy access:
"classification as definite RA is based upon the presence of synovitis in at least one joint, the absence of an alternative diagnosis that better explains the synovitis, and the achievement of a total score of at least 6 (of a possible 10) from the individual scores in four domains [9,10,13]. The highest score achieved in a given domain is used for this calculation. These domains and their values are:
●Number and site of involved joints
•2 to 10 large joints (from among shoulders, elbows, hips, knees, and ankles) = 1 point
•1 to 3 small joints (from among the metacarpophalangeal joints, proximal interphalangeal joints, second through fifth metatarsophalangeal joints, thumb interphalangeal joints, and wrists) = 2 points
•4 to 10 small joints = 3 points
•Greater than 10 joints (including at least 1 small joint) = 5 points
●Serological abnormality (rheumatoid factor or anti-citrullinated peptide/protein antibody)
•Low positive (above the upper limit of normal [ULN]) = 2 points
•High positive (greater than three times the ULN) = 3 points
●Elevated acute phase response (erythrocyte sedimentation rate [ESR] or C-reactive protein [CRP]) above the ULN = 1 point
●Symptom duration at least six weeks = 1 point
In addition to those with the criteria above, which are best suited to patients with newly presenting disease, the following patients are classified as having RA:
●Patients with erosive disease typical of RA with a history compatible with prior fulfillment of the criteria above
●Patients with longstanding disease, including those whose disease is inactive (with or without treatment) who have previously fulfilled the criteria above based upon retrospectively available data"
Hope this information is helpful and your rheumatologist should be able to answer any questions on what points are derived from your examination. Best, Richard (RheumatoidArthritis.net Team)