Drews C, Greenland S, Flanders W D
Division of Epidemiology, Emory University School of Medicine, Atlanta, GA.
Ann Epidemiol. 1993 Jan;3(1):86-92. doi: 10.1016/1047-2797(93)90014-u.
Recall bias or report bias is said to occur when associations are distorted or created because case informants report events differently from controls. Some investigators have suggested that this bias can be prevented by choosing controls who have conditions similar to those found in the case group. We use the term "restricted-control group" for such a control series. Although using a restricted-control series may eliminate differential misclassification, this approach will usually not eliminate nondifferential misclassification and may create selection bias. In this article, we present a way to algebraically examine the effects of misclassification and selection bias on observed associations. We use this method to compare the impact of recall bias in a study using a population control group with the effects of selection bias and nondifferential misclassification if a restricted-control group is used. Our approach is exemplified using data from a case-control study of sudden infant death syndrome. Our findings show that even when recall bias exists, the observed association can be closer to the true association when a population control series is used than when a restricted-control group is used.
当病例报告者与对照报告事件的方式不同，导致关联被扭曲或人为制造时，就会出现回忆偏倚或报告偏倚。一些研究者认为，通过选择与病例组情况相似的对照可以预防这种偏倚。我们将这样的对照系列称为“受限对照组”。虽然使用受限对照组可能消除差异错分，但这种方法通常无法消除非差异错分，且可能产生选择偏倚。在本文中，我们提出一种代数方法来检验错分和选择偏倚对观察到的关联的影响。我们用这种方法比较了在一项使用人群对照组的研究中回忆偏倚的影响，以及如果使用受限对照组时选择偏倚和非差异错分的影响。我们以一项婴儿猝死综合征病例对照研究的数据为例阐述我们的方法。我们的研究结果表明，即使存在回忆偏倚，使用人群对照组时观察到的关联也可能比使用受限对照组时更接近真实关联。
