The American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR) worked together to develop the 2010 Rheumatoid Arthritis Classification Criteria for rheumatoid arthritis.1 The goal is to identify possible rheumatoid arthritis early so there is no delay in starting treatment.
The classification criteria are used to evaluate people who have swelling in at least one joint that is not explained by another disease such as lupus or gout. An evaluation results in a score between 0 and 10. Rheumatoid arthritis is diagnosed if the score is 6 or more. Here is a summary of the criteria.1
|The number and size of joints that are swollen. The doctor counts how many large joints (shoulders, elbows, hips, knees, ankles) and how many small joints (the small joints in the wrists, hands, and feet) are swollen. You may hear these criteria called "joint involvement."||You get a score from 0 to 5.|
|Blood tests. The part of the blood called "serum" is evaluated to look for rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP or ACPA). These are usually higher than normal in people who have rheumatoid arthritis. You may hear these criteria called "serology."||You get a score from 0 to 3.|
|Additional blood tests. The blood is also tested for C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR or sed rate). These tests show whether there is inflammation in the body. You may hear these criteria called "acute-phase reactants."||You get a score of 0 or 1.|
|How long symptoms have lasted. The doctor notes whether symptoms have lasted less than 6 weeks, or 6 or more weeks. You may hear these criteria called "duration of symptoms."||You get a score of 0 or 1.|