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Classification Criteria for Rheumatoid Arthritis

Finding

Score

Criteria for evaluation:

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

  • Synovitis not better explained by another disorder

Classification criteria for rheumatoid arthritis is a score-based algorithm. Scores for categories A‒D are added; a score ≥ 6 (highest possible total 10) is needed to classify a patient as having definite rheumatoid arthritis.a

A. Joint involvementb

1 large jointc

0

2‒10 large joints

1

1‒3 small jointsd (with or without involvement of large joints)

2

4‒10 small joints (with or without involvement of large joints)

3

>10 jointse (at least 1 small joint)

5

B. Serology (at least 1 test result is needed for classification)

Negative RF and negative anti-CCP

0

Low-positivef RF or low-positive anti-CCP

2

High-positiveg RF or high-positive anti-CCP

3

C. Acute-phase reactants (at least 1 test result is needed for classification)

Normal CRP and normal erythrocyte sedimentation rate

0

Abnormal CRP or abnormal erythrocyte sedimentation rate

1

D. Duration of symptoms (based on patient's report)

< 6 weeks

0

≥ 6 weeks

1

a Patients with a score of < 6 can be reassessed; they may meet the criteria for rheumatoid arthritis cumulatively over time.

b Distal interphalangeal joints, first carpometacarpal joints, and first metatarsophalangeal joints are excluded from assessment.

c Large joints are the shoulders, elbows, hips, knees, and ankles.

d Small joints are the metacarpophalangeal joints, proximal interphalangeal joints, 2nd‒5th metatarsophalangeal joints, thumb interphalangeal joints, and wrists.

e These joints may include other joints not specifically listed elsewhere (eg, temporomandibular, acromioclavicular, sternoclavicular).

f Low positive indicates levels between 1 and 3 times the upper limit of normal.

g High positive indicates levels at least 3 times the upper limit of normal.

Anti-CCP = anticitrullinated protein antibody; CRP = C-reactive protein; RF = rheumatoid factor.

Adapted from Aletaha D, Neogi T, Silman AJ, et al: 2010 Rheumatoid arthritis classification criteria: An American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum 62 (9):2569–2581, 2010.

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