Institute for Mathematics and Its Applications
Talk abstract:
Data are often clustered in correlated groups in medical studies. Endpoints of interest may include the cluster size and/or one or more binary outcomes on each unit within a cluster. In vaccine and toxicology applications the effect of an exposure on the cluster size can be assumed to be isotonic. A variety of resampling methods are proposed for imputing the potential cluster sizes in the absence of exposure under this assumption. Standard models can then be fit to estimate a dose-response relationship or to test for an overall toxic effect. These methods are applied to data sets and are evaluated through simulation studies. Fully nonparametric and Bayesian alternatives are proposed.