Machado S G, Bailey K R
Biometrics. 1985 Jun;41(2):539-45.
Two substances interact if the combined action results in an effect which is greater than, or less than, that of the sum of the effects produced separately by the substances. Finney (1971, Probit Analysis, 3rd ed. Cambridge: Cambridge University Press) proposed a probabilistic model for simple independent action of two substances for the case of dichotomous outcomes. Using Finney's underlying model, we examine tests for interaction between carcinogens or toxic substances for data from long-term 2 x 2 and 2 x 2 x 2 factorially designed animal experiments. The outcome of interest is the occurrence or not of a certain event (for example, the appearance of a tumor) and the time at which the event occurred. The proposed tests are based on the proportional hazards model. We discuss some simple methods for checking the appropriateness of the proportional hazards assumption. Applications of the tests are made to data from a 2 x 2 and a 2 x 2 x 2 experiment.
如果两种物质共同作用产生的效应大于或小于它们分别产生的效应之和，那么这两种物质就会发生相互作用。芬尼（1971年，《概率分析》，第三版。剑桥：剑桥大学出版社）针对二分类结局的情况，提出了一个关于两种物质简单独立作用的概率模型。利用芬尼的基础模型，我们针对长期2×2和2×2×2析因设计动物实验的数据，研究致癌物或有毒物质之间相互作用的检验方法。感兴趣的结局是某个特定事件的发生与否（例如肿瘤的出现）以及该事件发生的时间。所提出的检验方法基于比例风险模型。我们讨论了一些用于检验比例风险假设是否恰当的简单方法。这些检验方法应用于来自一个2×2实验和一个2×2×2实验的数据。
