Estimation of cancer mortality rates: a Bayesian analysis of small frequencies.

A Bayesian method is presented for estimating mortality rates of specific diseases when the frequency of deaths over a specified time period is assumed to have a Poisson distribution with mean proportional to the population size. The estimators use information from related populations, each having its own rate which is assumed distributed according to a common prior distribution about which some information is available. The study was motivated by an epidemiological study on the geographic variation of cancer mortality in the state of Missouri. Data from this study are used to illustrate the method and to compare it to a somewhat simpler empirical Bayes method.