Premium
Marginal Analyses of Clustered Data When Cluster Size Is Informative
Author(s) -
Williamson John M.,
Datta Somnath,
Satten Glen A.
Publication year - 2003
Publication title -
biometrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.298
H-Index - 130
eISSN - 1541-0420
pISSN - 0006-341X
DOI - 10.1111/1541-0420.00005
Subject(s) - generalized estimating equation , resampling , marginal model , mathematics , replicate , cluster (spacecraft) , statistics , sample size determination , equivalence (formal languages) , estimating equations , gee , computer science , regression analysis , maximum likelihood , discrete mathematics , programming language
Summary . We propose a new approach to fitting marginal models to clustered data when cluster size is in‐ formative. This approach uses a generalized estimating equation (GEE) that is weighted inversely with the cluster size. We show that our approach is asymptotically equivalent to within‐cluster resampling (Hoffman, Sen, and Weinberg, 2001, Biometrika 73, 13–22), a computationally intensive approach in which replicate data sets containing a randomly selected observation from each cluster are analyzed, and the resulting estima‐ tes averaged. Using simulated data and an example involving dental health, we show the superior performa‐ nce of our approach compared to unweighted GEE, the equivalence of our approach with WCR for large sam‐ ple sizes, and the superior performance of our approach compared with WCR when sample sizes are small.