Modified Weibull multi-state models for the analysis of animal carcinogenicity data |
| |
Authors: | Nigel Stallard Anne Whitehead |
| |
Institution: | (1) Medical and Pharmaceutical Statistics Research Unit, The University of Reading, PO Box 240, Earley Gate, Reading, Berkshire, RG6 6FN, UK |
| |
Abstract: | The Peto test is the standard method of analysis used in carcinogenicity studies to compare tumor incidence in groups of animals. It assumes that tumors are either instantly fatal or have no effect on mortality and requires a judgement of the lethality of each tumor. To avoid this requirement, parametric multi-state models have been proposed. In addition these allow estimation of tumor onset and mortality rates. This paper considers two such models and presents a modification. It is shown that the modified models provide a better fit to carcinogenicity data and simulated data are used to show that the modified models provide a modest increase in test power relative to the Peto test. |
| |
Keywords: | Peto test survival/sacrifice experiments tumor data simulation |
本文献已被 SpringerLink 等数据库收录! |