[R] zero cells in one variable in logistic regression

[David Winsemius]

On Jul 13, 2009, at 5:37 AM, anna.bucharova wrote:

>
> Dear all.
> I am sort of beginner with R. I do logistic regression with binomial
> response variable and several continuous and categorical variables.  
> In one
> categorical variable, zero cell occures (2x2 table looks like
> 7 - 0
> 23 - 25
> This leads to overestimating of odds ratio and inflated confidence  
> interval
> for odds for given variable. The variable is significant in  
> univariate test.
> I do not necessarilly need odd ratio, but I need the explained  
> deviance by
> this variable and I really want to keep this variable in the model. It
> probably matters for explained deviance. How to treat this problem?
> Thanks for help, Anna Bucharova
> -- 

You might consider glmrob in package:robustbase. See http://www.jstatsoft.org/v10/i04

David Winsemius, MD
Heritage Laboratories
West Hartford, CT