[Application of ROC curve for evaluation of the effect of prenatal screening during second trimester of pregnancy].
OBJECTIVE
To develop a method for evaluating the feasibility of prenatal screening using local median value and determining the cut-off value.


METHODS
With receiver operating characteristic curve (ROC) analysis, results of second trimester prenatal screening calculated by a local median value in a new model and the built-in median value in 2T software were compared. The cut-off value was set by serial analysis of true and false positive rates and other relevant data.


RESULTS
The ROC curve has accurately estimated the difference in the screening efficacy between a local median value and that embedded in the 2T model, and established a reasonable cut-off value for the laboratory based on false positive rate and detection rate.


CONCLUSIONS
The method of ROC curve can be used to evaluate the performance of local median value in prenatal screening and to test the rationality of cut-off value established in the laboratory. As the result, a better cut-off value may be derived.
Weihai Maternal and Child Hospital, Weihai, Shandong 264200, P. R. China. Email: xinqiangl@126.com.
Xin-qiang
XQ
Lan
Lin-yuan
LY
Niu
Zhi-guang
ZG
Wu
Chun-xiao
CX
Zhang
Xiao-li
XL
Chen
D002681:China / Q000453:epidemiology; D004314:Down Syndrome / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011262:Pregnancy Trimester, Second / Q000235:genetics*; D011296:Prenatal Diagnosis / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D012372:ROC Curve; D012984:Software