Bayesian Analysis with Surrogate Outcomes In Experiments: Application To Bridging Human and Macaque Randomized Studies Of Anthrax Vaccine

• Activity Number: 161
• Type: Invited
• Date/Time: Tuesday, August 13, 2002 : 8:30 AM to 10:20 AM
• Sponsor: Section on Bayesian Stat. Sciences*
• Author(s): Donald Rubin*+
• Affiliation(s): Harvard University

Abstract

A CDC panel to help design experiments of anthrax vaccine was convened prior to September 11 because of concern with the current vaccine, such as how it should be delivered to minimize negative side effects. This question was considered especially important because of fears of the possible use of anthrax as a biological weapon. The two months since have proved these fears to be not as hypothetical as we all would have wished. This presentation will discuss critical design and analysis issues for using a combination of proposed randomized experiments with human volunteers and others with macaques, where in the former only surrogate outcomes (e.g., anti-body levels) will be available whereas in the later, surrogate outcomes and actual survival outcomes will be available. The proper "bridging" analyses of such studies involve statistical methods that are beyond standard formulations, and rely on the concept of "principal" stratification (Frangakis and Rubin, 2002, Biometrics). The role of Bayesian methods, including as implemented by multiple imputation, is the topic of this presentation.