van Straalen et al reported a model for predicting uveitis in a patient with juvenile idiopathic arthritis (JIA). The authors are from multiple institutions in Europe, Israel, Singapore and Brazil.
Patient selection: juvenile idiopathic arthritis
Parameters:
(1) ANA status
(2) age at JIA onset
(3) category of JIA
Parameter
Finding
Beta-Coefficient
ANA status
negative
0
positive
0.70
age on JIA onset
-0.17 * (age)
type of arthritis
oligoarthritis
0
systemic arthritis
-3.32
RF-positive polyarthritis
-2.78
RF-negative polyarthritis
-0.60
psoriatic arthritis
-0.17
enthesitis-related arthritis
0.42
undifferentiated arthritis
0.10
where:
• Rheumatoid factor (RF) is positive if there are at least 2 positive tests at least 3 months apart.
• The criteria for a positive ANA is not stated.
value of X =
= SUM(beta coefficients for all of the parameters) - 0.63
probability of uveiti =
= 1 / (1 + EXP((-1) * X))
Perforrmance:
• The area under the ROC curve is 0.75.
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