Evaluation of second trimester maternal serum screening for Down's syndrome using the Spiegelhalter-Knill-Jones (S-KJ) approach
Journal
Journal of Perinatal Medicine
Journal Volume
32
Journal Issue
5
Pages
407-412
Date Issued
2004
Author(s)
Abstract
Risk estimation for Down's syndrome in antenatal serum screening with maternal age and multiple serum biomarkers is usually complicated and computationally intensive. We have developed a simple scoring system using the Spiegelhalter-Knill-Jones approach, which was based on Bayesian theorem and the logistic regression model. A prospective data set with 3842 singleton pregnancies including 6 affected pregnancies served as "trained data". Maternal age, maternal serum alpha-fetoprotein and human chorionic gonadotrophin levels of each pregnant woman were adopted as the predictors to establish the scoring model using the S-KJ approach. Model validation was undertaken using a receiver operating characteristics (ROC) curve with another 3050 singleton pregnancies including 4 affected pregnancies ("validated data"). For the trained data the sensitivity and specificity of the scoring system at cut-off value of 1:250 was 66.7% and 92.6%, respectively. For the validated data the sensitivity and specificity at the same cut-off point was 75% and 92.2%, respectively. The area under the ROC curve of the trained and validated data was 76.96% (95% CI: 51.80-100%), and 94.07% (95% CI: 84.47-100%), respectively. The S-KJ scoring system has been demonstrated to be a simple, and efficient method for the risk estimation of Down's syndrome. This system can be applied to other antenatal serum screening systems.
SDGs
Type
journal article