|
Activity Number:
|
337
|
|
Type:
|
Contributed
|
|
Date/Time:
|
Tuesday, July 31, 2007 : 2:00 PM to 3:50 PM
|
|
Sponsor:
|
Section on Bayesian Statistical Science
|
| Abstract - #308461 |
|
Title:
|
Bayesian Power and Sample Size Calculations for Multicenter Clinical Trials with Binary Responses
|
|
Author(s):
|
Emine O. Bayman*+ and Kathryn Chaloner and Mary K. Cowles
|
|
Companies:
|
The University of Iowa/Uludag University and The University of Iowa and The University of Iowa
|
|
Address:
|
4155 WL, Dept of Biostatistics, Iowa City, IA, 52242,
|
|
Keywords:
|
Bayesian power ; Bayesian sample size ; Multi-center clinical trials ; Binary response
|
|
Abstract:
|
An important issue is to decide the total sample size and sample size for each center in a multi-center clinical trial. A Bayesian hierarchical model for binary responses representing success or failure is assumed, with exchangeable random center effects. A concept of Bayesian power is defined as the probability of reaching a specific conclusion for a fixed set of parameter values. An algorithm is described for determining the sample size to give appropriate Bayesian power. It is assumed that there are 2 treatments and N centers. Each center has a pre-specified relative ability to enroll. In addition, the impact of balance and imbalance between sample sizes in each center on power is examined. The algorithm is implemented using WinBUGS and R, and the R2WinBUGS interface.
|
