The incorporation of historical control information in tests of proportions: simulation study of Tarone's procedure.

Empirical Bayes procedures for incorporating historical control information in bioassay carcinogenesis studies are receiving attention in the literature. In general, the empirical Bayes methods fail to take into account the error in estimating the parameters of a prior distribution. The implications of this are studied for the beta prior of Tarone (1982, Biometrics 38, 215-220). Using simulations, we show that the skewness in the maximum likelihood estimators for the parameters of the beta prior increases the false positive rate in the test of dose-related trend.