ROC曲线下面积估计的参数法与非参数法的应用研究

目的:阐明ROC曲线下面积估计的参数法和非参数法并进行比较,为其在诊断试验评价中的应用提供依据.方法:用双正态模型的参数法和Mann-Witney统计量的非参数法估计ROC曲线下面积,并以其在肺癌诊断试验准确度评价中的应用来具体说明.结果:非参数法估计的肺癌两个标志物Cyfra21-1和CEA的ROC曲线下面积分别为0.77、0.87,参数法估计的面积分别为0.78、0.87,表明在样本量较大时参数法和非参数法估计的ROC曲线下面积近似相等.结论:样本量较小时可选择非参数法估计ROC曲线下面积,样本量较大时可根据实际情况选择参数法或非参数法.

Application of parametric method and non-parametric method in estimation of area under ROC curve

Objective:To elucidate and compare the parametric method and non-parametric method in estimation of the area under ROC curve,so as to provide a basis for their application in diagnosis assessment.Methods: The areas under ROC curves were estimated by parametric method of fitting binomial model and by non-parametric method of Mann-Witney statistics.The method was employed in the diagnostic tests of lung cancer.Results: By non-parametric methods,the areas under ROC curves of Cyfra21-1 and CEA were respectively 0.77 and 0.87 in the lung cancer diagnostic tests;by parametric methods,they were(0.78) and 0.87,respectively.It was indicated that when the sample size was large,the values of areas under ROC Curves were similar between parametric method and non-parametric method.Conclusion: Non-parametric method should be used to evaluate the area under ROC curve if the sample size is small,and for large sample size,the parametric method or nonparametric method should be chosen according to the actual situation.