Refreshments: MDS 312 @ 15:30

Abstract:

For clinical trials with survival data, the hazard ratio has been the most widely used measure for describing the treatment effect. The short-term and long-term hazard ratio model of Yang and Prentice (2005) contains the proportional hazards model and the proportional odds model as sub-models, and do not have restrictions such as zero or infinite hazard ratio in the short term or long term, that many other semi-parametric models impose. Thus it provides sufficient flexibility when there is possibly a treatment by time interaction. We investigate various measures under this model. Point estimates, point-wise confidence intervals and simultaneous confidence bands of the hazard ratio and a few other measures are established. These results can be used to capture and to graphically present the treatment effect. We also investigate extension of the model to allow covariate adjusted analysis. We illustrate these visual tools and discuss their merits and limitations in applications to clinical trials including the Women's Health Initiative.