Statistical assessment of mediational effects for logistic mediational models
Statistical assessment of mediational effects for logistic mediational models
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DOI：
10.1002/sim.1847
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发表时间：
2004-09-17
影响因子：
2
通讯作者：
Goodman, E
中科院分区：
文献类型：
--
作者：
Bin, H;Sivaganesan, S;Goodman, E
调解的概念在医学卫生研究中有着广泛的应用。虽然在正态假设下对中介效应的统计评估已经在线性结构方程模型中得到了很好的建立，但它还没有扩展到正态不是通常假设的一般情况。在本文中，我们建议通过因果推理来扩展中介效应的定义。新定义与线性结构方程的定义一致，不依赖于正态分布的假设。这里，我们将注意力集中在Logistic中介模型上，其中涉及的所有变量都是二进制的。研究了估计中介效应的三种方法--Delta方法、Bootstrap方法和基于蒙特卡罗模拟的贝叶斯模型。模拟研究被用来检验这三种方法的行为。以95%可信区间(CI)覆盖率和均方根误差(RMSE)标准衡量，发现使用非信息性先验的贝叶斯方法优于Bootstrap和Delta方法，特别是在小样本容量的情况下。通过一个具有全国代表性的数据库，展示了所提出的方法在公共卫生研究中的应用。文中还讨论了将该方法扩展到其他类型的中介模型和多个中介的问题。版权所有(C)2004 John Wiley Sons，Ltd.
The concept of mediation has broad applications in medical health studies. Although the statistical assessment of a mediational effect under the normal assumption has been well established in linear structural equation models (SEM), it has not been extended to the general case where normality is not a usual assumption. In this paper, we propose to extend the definition of mediational effects through causal inference. The new definition is consistent with that in linear SEM and does not rely on the assumption of normality. Here, we focus our attention on the logistic mediation model, where all variables involved are binary. Three approaches to the estimation of mediational effects-Delta method, bootstrap, and Bayesian modelling via Monte Carlo simulation are investigated. Simulation studies are used to examine the behaviour of the three approaches. Measured by 95 per cent confidence interval (CI) coverage rate and root mean square error (RMSE) criteria, it was found that the Bayesian method using a non-informative prior outperformed both bootstrap and the Delta methods, particularly for small sample sizes. Case studies are presented to demonstrate the application of the proposed method to public health research using a nationally representative database. Extending the proposed method to other types of mediational model and to multiple mediators are also discussed. Copyright (C) 2004 John Wiley Sons, Ltd.