HOW INDEPENDENT ARE INDEPENDENT EFFECTS - RELATIVE RISK-ESTIMATION WHEN CORRELATED EXPOSURES ARE MEASURED IMPRECISELY
HOW INDEPENDENT ARE INDEPENDENT EFFECTS - RELATIVE RISK-ESTIMATION WHEN CORRELATED EXPOSURES ARE MEASURED IMPRECISELY
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DOI：
10.1016/0895-4356(91)90155-3
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发表时间：
1991-01-01
影响因子：
7.2
通讯作者：
SMITH, GD
中科院分区：
文献类型：
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作者：
PHILLIPS, AN;SMITH, GD
如果暴露于随机测量误差或受试者内部变异性，则与疾病风险暴露有关的相对风险估计往往过于接近统一。对于一次暴露的影响，在对混杂暴露进行调整后，“独立的”相对风险估计可能在两个方向上都有偏差，这取决于在感兴趣的暴露和混杂因素中的测量不精确度。我们描述了两种方法，它们估计多变量相对风险估计中由于模型中一个或多个暴露变量的测量不精确度的影响而产生的偏差。在一个涉及高密度脂蛋白、甘油三酯和冠心病的例子中，对两种方法的结果进行了比较。在这个例子中，相对风险估计的偏差程度高度依赖于归因于暴露的测量不精确度。结论是，当两个曝光量基本相关，且其中一个或两者都受到相当大的测量不精确度的影响时，只测量一次曝光量的研究将不足以调查曝光的独立影响。在可行的情况下，流行病学家应该寻找暴露之间相关性较小的研究人群。
A relative risk estimate which relates an exposure to risk of disease will tend to be estimated too close to unity if that exposure is subject to random measurement error or intra-subject variability. "Independent" relative risk estimates, for the effect of one exposure after adjusting for confounding exposures, may be biased in either direction, depending on the amount of measurement imprecision in the exposure of interest and in the confounders. We describe two methods which estimate the bias in multivariate relative risk estimates due to the effect of measurement imprecision in one or more of the exposure variables in the model. Results from the two methods are compared in an example involving HDL cholesterol, triglycerides and coronary heart disease. In this example, the degree of bias in relative risk estimates is shown to be highly dependent on the amount of measurement imprecision ascribed to the exposures. It is concluded that when two exposures are substantially correlated, and one or both is subject to sizeable measurement imprecision, a study in which exposures are measured only once will be inadequate for investigating the independent effect of the exposures. Where feasible, epidemiologists should seek study populations where the correlation between the exposures is smaller.