Confidence Intervals for the Difference Between Two Median Survival Times for Clustered Survival Data

• Activity Number: 173
• Type: Topic Contributed
• Date/Time: Monday, August 10, 2015 : 10:30 AM to 12:20 PM
• Sponsor: Section on Risk Analysis
• Author(s): Yu-Mei Chang*
• Keywords: Clustered survival data ; Confidence interval ; Shared gamma frailty model ; Median survival time

Abstract

Clustered survival data arise often in clinical trials, where the correlated subunits from the same cluster are randomized to different treatment groups. To test the equality of marginal survival distributions between two treatment groups, we need to consider the intracluster correlations both within and between treatment groups. In this article, we consider the construction of the conditional confidence interval for the difference of two median survival times given the covariates under a shared gamma frailty model for clustered survival data. Based on the conditional confidence intervals, we can identify the possible range of covariates over which the two groups would provide different median survival times.