Abstract

Analysis of clustered binary data with covariates specific to each observation

Geys, H., Molenberghs, G., and Williams, P.

The standard approach for analysis of teratology studies is to use a population-averaged model with primary interest on evaluating dose-response effects. For example, generalized estimating equations (GEEs) have become popular for analysis of both developmental toxicity and reproductive studies (Ryan, 1992). Such an approach is typically appropriate, since the covariate of interest --exposure level-- is constant for each litter of animals. Recently, however, there has been growing interest in evaluating effects of covariates which can vary between individuals within a cluster. This paper explores several opportunities generated by teratology studies with individual-level covariates both in terms of modelling approaches and in decomposition of litter effects into genetic and environmental components.

  Last update: January, 24, 2003  - Contact : S. Malali