He et al reported a model and nomogram for predicting norovirus infection in a pediatric patient. The authors are from Sun Yat-Sen University and Shenzhen Children's Hospital in China.
Patient selection: pediatric patient with symptoms of acute gastroenteritis
Parameters:
(1) upper respiratory infection (URI)
(2) vomiting
(3) platelet count in 10^9/L, from 64 to 658
(4) WBC count in 10^9/L, from 3.18 to 33.80
(5) lymphocyte count in 10^9/L (LC), from 0.85 to 13.42
points for platelet count =
= (0.015 * (platelet count)) + 0.0303
points for WBC count =
= (0.074 * (WBC count)) - 0.0115
points for lymphocyte count =
= (0.04455 * (lymphocyte count)) - 0.038
|
Parameter
|
Finding
|
Points
|
|
upper respiratory infection
|
no
|
0
|
|
|
yes
|
0.79
|
|
vomiting
|
no
|
0
|
|
|
yes
|
1.7
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 15.55
value of X =
= (0.7273 * (score)) - 4.605
probability of norovirus infection =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.827 in the training and 0.812 in the validation cohorts.
