Confidence Bands for the Treatment Effect with Survival Data

• Activity Number: 22
• Type: Topic Contributed
• Date/Time: Sunday, August 4, 2013 : 2:00 PM to 3:50 PM
• Sponsor: Biometrics Section
• Author(s): Song Yang*+ and Ross Prentice
• Companies: NIH/NHLBI and Fred Hutchinson Cancer Research Center
• Keywords: Confidence Bands ; Treatment Effect ; Survival Data ; Time-dependence ; Covariate Adjustment ; Clinical Trial

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 provides sufficient flexibility when there is possibly a treatment by time interaction. We extend the model to allow covariate adjustment and investigate various measures for the treatment effect. 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 illustrate these visual tools and discuss their merits and limitations in applications to clinical trials including the Women's Health Initiative.