Chinchilli V M, Clark B C
Department of Biostatistics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.
Environ Health Perspect. 1989 Feb;79:217-21. doi: 10.1289/ehp.8979217.
The data from developmental toxicity experiments usually are very difficult to analyze statistically because of the lack of independence among littermates and the random nature of the litter size. Only a few of the models that have been proposed in the literature have accounted for both of these features. One of the models proposed by Van Ryzin is invoked to construct a test of trend (dose response). The construction is achieved via a statistical technique called isotonic regression, which is applied to the moment estimators derived by Van Ryzin. The trend test based on isotonic regression is relatively straightforward to calculate, and when the number of dose groups (including control) is four or less, the significance of the observed result is easily determined. An example, in which fetolethality is the end point of interest, demonstrates the test.
发育毒性实验的数据通常很难进行统计分析，因为同窝幼仔之间缺乏独立性且窝仔大小具有随机性。文献中提出的模型中只有少数考虑到了这两个特征。范·里津提出的模型之一被用来构建趋势检验（剂量反应）。通过一种称为保序回归的统计技术来实现构建，该技术应用于范·里津推导的矩估计量。基于保序回归的趋势检验计算相对简单，当剂量组（包括对照组）数量为四个或更少时，很容易确定观察结果的显著性。以胎儿致死率为感兴趣终点的一个例子说明了该检验。
