Multiple logistic Regression Power Analysis

[Canyon75]

Hi to everybody,

Please does anybody can help me to solve this problem?
I have a multiple logistic regression model with more than one BINARY INDEPENDENT VARIABLES.
I need to calculate the minimum required sample size for my study, and I perfectly know how to calculate that for a model with only one binary independent variable (http://www.psycho.uni-duesseldorf.de/abteilungen/aap/gpower3/user-guide-by-distribution/z/logistic_regression).
But I cannot find on web any material or documentation illustrating a solution to the problem with a multiple logistic regression model with more that one binary independent variables

Will you, please, help me?????
I'd appreciate it very very much.

[TheAnalysisFactor]

I think you'll have a hard time doing that by hand. At least I would.

You need some sample size software. I like StudySize, but I just checked and it will only do one covariate for a logistic regression.

I don't have it anymore, but I'm pretty sure nQuery can do it. It is the premiere sample size software. It's expensive, unfortunately.

Karen