title: The use of a correlated binomial model for the analysis of certain toxicological experiments.
abstract: In certain toxicological experiments with laboratory animals, the outcome of interest is the occurrence of dead or malformed fetuses in a litter. Previous investigations have shown that the simple one-parameter binomial and Poisson models generally provide poor fits to this type of binary data. In this paper, a type of correlated binomial model is proposed for use in this situation. First, the model is described in detail and is compared to a beta-binomial model proposed by Williams (1975). These two-parameter models are then contrasted for goodness of fit to some real-life data. Finally, numerical examples are given in which likelihood ratio tests based on these models are employed to assess the significance of treatment-control differences.
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000453:epidemiology*; D000818:Animals; D000830:Animals, Laboratory; D005260:Female; D005313:Fetal Death / Q000139:chemically induced* / Q000453:epidemiology; D008098:Litter Size; D008954:Models, Biological; D011247:Pregnancy; D011336:Probability; D013223:Statistics as Topic; D014116:Toxicology / Q000379:methods*