Re: st: XTGEE of morbidity data

["Sarah A. Mustillo" <smustillo@psych.mc.duke.edu>]

Hi -

The best source of information on goodness of fit for GEE models is the 
Hardin & Hilbe book:

http://www.stata.com/bookstore/gee.html

Here is an excerpt from the table of contents:

4 Residuals, Diagnostics, and Testing

4.1 Criterion measures
4.1.1 Choosing the best correlation structure
4.1.2 Choosing the best subset of covariates
4.2 Analysis of residuals
4.2.1 A nonparametric test of the randomness of residuals
4.2.2 Graphical assessment
4.2.3 Quasivariance functions for PA-GEE models
4.3 Deletion diagnostics
4.3.1 Influence measures
4.3.2 Leverage measures
4.4 Goodness of fit (population-averaged models)
4.4.1 Proportional reduction in variation
4.4.2 Concordance correlation
4.4.3 A x2 goodness of fit test for PA-GEE binomial models
4.5 Testing coefficients in the PA-GEE model
4.5.1 Likelihood ratio tests
4.5.2 Wald tests
4.5.3 Score tests
4.6 Assessing the MCAR assumption of PA-GEE models
4.7 Summary 4.8 Exercises



Sarah

--On Thursday, June 19, 2003 4:20 PM -0500 Mike Sanderson 
<Sandersn@vet.k-state.edu> wrote:


> I have a dataset of weekly morbidity counts and populations at risk from
> 123 pens of feedlot cattle.
> Have run XTGEE family Poisson, log link, t(week) i(pen number) exp(pop
> at risk)
>
> Are there any goodness of fit statistics for this model? I have been
> unable to find any. Does any one have suggestions of how to assess the
> fit or a better way to deal with the data?
>
> Thanks
>
>
>
> Mike Sanderson DVM, MS, DACVPM, DACT
> Associate Professor, Beef Production
> Kansas State University, College of Veterinary Medicine
> Ph: 785-532-5700,  FAX 785-532-4989
> sandersn@vet.k-state.edu
> *
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Sarah A. Mustillo, Ph.D
Department of Psychiatry and Behavioral Sciences
Duke University School of Medicine
Box 3454
Durham NC 27710

919 687-4686 x241
*
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