A result on a 2 x 2 survival experiment.
Lifetime data classified according to categorical variables under the proportionality of the hazard functions of response variables for various treatment combinations is assumed. The proposed model is a combination of Cox's proportional hazards model and ANOVA model. The existence of a solution to the marginal likelihood function is examined for the case of 2 x 2 two-way classification. We provide an easily verifiable condition for the existence of a unique estimate.
Arani
R B
RB
Division of Biometry and Risk Assessment, National Center for Toxicological Research, Jefferson, Arkansas 72079-9502, USA.
Rao
M B
MB
D006801:Humans; D015993:Life Tables; D008433:Mathematics; D011336:Probability; D016016:Proportional Hazards Models; D016019:Survival Analysis