Vanier et al reported a model for predicting rapid radiographic progression for a patient with early rheumatoid arthritis. The authors are from multiple institutions in Europe.
Patient selection: early rheumatoid arthritis
Parameters:
(1) rheumatoid factor
(2) number of rheumatoid arthritis erosions on X-rays
(3) serum CRP in mg/L
(4) number of swollen joints out of 28
Parameter
Finding
Points
rheumatoid factor
negative
0
positive
0.77
erosions on X-rays
0
0
>= 1
0.81
serum CRP
< 10 mg/L
0
10 to 30 mg/L
0.17
> 30 mg/L
0.77
swollen joint count
< 7
0
7 to 10
0.03
> 10
0.39
where:
• The matrix tool uses swollen joint count < 6 rather than < 7 for first group. The third group is >= 10 rather than > 10.
value of X =
= SUM(points for all of the parameters) - 2.8
probability of early progression =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve was 0.63 to 0.68.
To read more or access our algorithms and calculators, please log in or register.
