Analysis of proportions of affected foetuses in teratological experiments.
This paper is concerned with the analysis of proportions affected when an increasing dose of a compound is applied to a group of laboratory animals. Several sets of data, including a set from a teratological experiment at the Shell Toxicology Laboratory, Sittingbourne, are analysed and some simulations are performed. Among the distributional models, the beta-binomial model is, in general, found to be the most sensitive to departures from the binomial. For testing the equality of two proportions, a comparison is made between the pseudo-t test, based on the jackknife method, and the likelihood ratio test, based on the beta-binomial model. From the limited comparison, no definite advantage of one approach over the other has been found; at the 5% level of significance both approaches lead to similar conclusions.
D000818:Animals; D000013:Congenital Abnormalities / Q000209:etiology; D005260:Female; D005333:Fetus / Q000187:drug effects*; D008433:Mathematics; D008954:Models, Biological; D011247:Pregnancy; D013723:Teratogens / Q000494:pharmacology*
D013723:Teratogens