Tumour incidence, prevalence and lethality estimation in the absence of cause‐of‐death information

Summary.  A Bayesian intensity model is presented for studying a bioassay problem involving interval‐censored tumour onset times, and without discretization of times of death. Both tumour lethality and base‐line hazard rates are estimated in the absence of cause‐of‐death information. Markov chain Monte Carlo methods are used in the numerical estimation, and sophisticated group updating algorithms are applied to achieve reasonable convergence properties. This method was tried on the rat tumorigenicity data that have previously been analysed by Ahn, Moon and Kodell, and our results seem to be more realistic.