Fig. 4

ROC Curve on the Predictive Value of USG in the VVS Diagnosis in Children and Adolescents. Notes: ROC curve on the predictive value of VVS diagnosis in children and adolescents with USG as the cut-off value. The vertical axis denotes the sensitivity of USG to the predictive value of VVS diagnosis, and the horizontal axis indicates the false positive rate (1-specificity), the solid line of 45°coordinate in the figure is criterion-referenced line, indicating that the sensitivity and the false positive rate is equal, no predictive value. The farther the curve is to the upper left of the reference line, the higher the predictive value is. The AUC represents the predictive value of USG in the diagnosis of VVS. The AUC value of 0.5 ~ 0.7 is low, 0.7 ~ 0.9 is medium, and > 0.9 is high