Four types of effect modification - A classification based on directed acyclic graphs
Four types of effect modification - A classification based on directed acyclic graphs
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DOI：
10.1097/ede.0b013e318127181b
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发表时间：
2007-09-01
期刊：
影响因子：
5.4
通讯作者：
Robins, James M.
中科院分区：
文献类型：
--
作者：
VanderWeele, Tyler J.;Robins, James M.
通过将条件因果风险差异表示为特定层风险差异和条件概率的乘积之和，可以对可能引起风险差异量表效应修改的因果关系类型进行分类。有向非循环图阐明了特定变量作为涉及2个其他变量的因果风险差异的效应修饰符所需的因果关系。因此，有向无环图因果框架产生了效果修改的4重分类：直接效果修改，间接效果修改，代理的效果修改和共同原因的效果修改。我们简要地讨论了多效应修正关系和多效应修正因子以及因果风险差异以外的效应度量的情况。
It is possible to classify the types of causal relationships that can give rise to effect modification on the risk difference scale by expressing the conditional causal risk-difference as a sum of products of stratum-specific risk differences and conditional probabilities. Directed acyclic graphs clarify the causal relationships necessary for a particular variable to serve as an effect modifier for the causal risk difference involving 2 other variables. The directed acyclic graph causal framework thereby gives rise to a 4-fold classification for effect modification: direct effect modification, indirect effect modification, effect modification by proxy and effect modification by a common cause. We briefly discuss the case of multiple effect modification relationships and multiple effect modifiers as well as measures of effect other than that of the causal risk difference.