2010 ACR/EULAR Classification Criteria for Rheumatoid Arthritis (RA)

A weighted classification tool for definite rheumatoid arthritis in patients with otherwise unexplained clinical synovitis.

At least 1 joint with definite clinical synovitis (swelling)*

Synovitis is not better explained by another disease*

Joint involvement*

1 large joint0

2-10 large joints+1

1-3 small joints (with or without involvement of large joints)+2

4-10 small joints (with or without involvement of large joints)+3

>10 joints (at least 1 small joint)+5

Serology*

Negative rheumatoid factor and negative anti-citrullinated protein antibody0

Low-positive rheumatoid factor or low-positive anti-citrullinated protein antibody+2

High-positive rheumatoid factor or high-positive anti-citrullinated protein antibody+3

Acute-phase reactants*

Normal CRP and normal ESR0

Abnormal CRP or abnormal ESR+1

Duration of symptoms*

<6 weeks0

≥6 weeks+1