[R] under (and over) dispersion in Poisson regression

From: John Sorkin <jsorkin_at_grecc.umaryland.edu>
Date: Wed 04 Jan 2006 - 02:46:26 EST


I am trying to use Poisson regression to model count data. My results are suggestive of under dispersion (0.79). How close to one does one want the measure of dispersion to be before one accepts the results of the analysis?

I know that there is no definitive answer to my question, but I would like to get some sense of general practice. Thanks,
John

John Sorkin M.D., Ph.D.
Chief, Biostatistics and Informatics
Baltimore VA Medical Center GRECC and
University of Maryland School of Medicine Claude Pepper OAIC

University of Maryland School of Medicine Division of Gerontology
Baltimore VA Medical Center
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524

410-605-7119
- NOTE NEW EMAIL ADDRESS:
jsorkin@grecc.umaryland.edu



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