Date:         Tue, 16 Oct 2007 12:52:35 +0300
Reply-To:     Irene Prix <irepri@utu.fi>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         Irene Prix <irepri@utu.fi>
Organization: University of Turku
Subject:      Estimating relative risk from logistic regression probabilities?
Content-type: text/plain; charset=ISO-8859-15; format=flowed

Hey there,

I was wondering if it's statistically "ok" to calculate the relative
risk comparing two groups by dividing their probabilities predicted by
the logistic regression model (e.g. men and women given the same values
on the rest of the predictors)? If so, how would I calculate a
confidence interval for this RR estimation?

The background to this question is that I would like to compare
different groups as to their probability to fall into the response
category. In the literature I found such comparisons made also by simply
calculating the differences between the probabilities of two groups of
interests. I was wondering if any one way is preferrable (ie. pr1/pr2 or
pr2-pr1)?

Any help or comments are greatly appreciated.

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