无金标准试验评价方法及其在唐氏综合征筛查中的应用

The Evaluation Method for a Test in the Absence of a Gold Standard and Application in Down's Syndrome Screening Test

目的介绍在无金标准情况下估计筛查试验参数的方法,评价唐氏综合征筛查试验。方法采用Gibbs抽样方法构造markov链,估计唐氏综合征筛查试验的参数。结果采用MCMC方法中的Gibbs抽样方法,估计出了利用母体血清AFP与游离beta Hcg结合母体年龄别危险度在国内人群中筛查唐氏综合征试验的ROC曲线,从而得了试验的灵敏度、特异度和合适的阈值。结论MCMC方法中的Gibbs抽样方法能够在缺少金标准的前提下,结合参数的先验分布较好地估计筛查试验的参数。

Objective This paper introduces the method for estimating parameters of a test in absence of a good standard and evaluates the parameters of Down＇s syndrome screening test in china with the methods. Methods We construct a markov chain base on Gibbs sample, with the property of the chain, the parameters of Down＇s syndromes screening test in china are evaluated. Results The ROC curve and the parameters of the screening test with the AFP and free beta Hcg in china, such as sensitivity, specificity, the cutoff level, are computed. Conclusion The methods of Gibbs sample in MCMC can evaluate the parameters of the test in absence of a good standard.