Table 2.

Revised categories and weights after inclusion of additional joint involvement category^*

Criterion and category	Score
Joint involvement (pattern and distribution)
1 medium-large joint	0.0
Asymmetric medium-large joints (at least 2 joints)	10.1
Symmetric medium-large joints (at least 2 joints)	16.0
1–3 small joints (hands/feet or wrists)	21.0
≥4 asymmetric small joints (hands/feet or wrists)	27.7
4–10 symmetric small joints (hands/feet or wrists)	29.4
>10 joints including hands/feet or wrists	50.5
Serology (ACPA or RF)
RF negative and ACPA negative	0.0
Low-positive (RF positive and/or ACPA positive)	21.8
High-positive (RF positive and/or ACPA positive)	33.6
Acute-phase reactants (CRP or ESR)
Normal	0.0
Abnormal	5.9
Duration of synovitis
<4 weeks	0.0
4–8 weeks	8.4
>8 weeks	10.1

^*Scores from each criterion are summed to derive the total score, which represents the probability of developing rheumatoid arthritis (RA).

ACPA = anti–cyclic citrullinated protein; RF = rheumatoid factor; CRP = C-reactive protein; ESR = erythrocyte sedimentation rate.