I would recommend not using the odds ratios, since there is a lot more
information in the other quantities available. (On this point, you might
see Gary King and Langche Zeng. 2002. ``Estimating Risk and Rate Levels,
Ratios, and Differences in Case-Control Studies,'' Statistics in Medicine,
Vol. 21, Pp. 1409-1427.
http://gking.harvard.edu/files/abs/1s-abs.shtml).
But if you'd still like them, what you should do is to calculate the two
base probabilities, which relogit gives, and compute the risk ratio (or
relative risk) from that. The odds ratio is an approximation to the risk
ratio anyway, so you'd certainly be better off with that, even aside from
the issues discussed in the article I mentioned. Of course you can still
calculate the OR from the base probabilities too if you like.
Gary
---
Gary King
Institute for Quantitative Social Science
Harvard University, 34 Kirkland St, Cambridge, MA 02138
http://GKing.Harvard.Edu, King(a)Harvard.Edu
Direct 617-495-2027, Assistant 495-9271, eFax 812-8581
On Mon, 11 Jul 2005, Martin.Ploederl(a)sbg.ac.at wrote:
Hi,
I'm glad to have relogit available in R, because I've rare event data
(suididology). Running relogit works fine. For publishing data, I need
as an output odds-ratios plus the confidence intervals for each
predictor. How can this be realized with Zelig? (Usually I use Frank
Harrels "ols" and "lrm" - functions which give me the odds ratios) I
would appreciate helping me with regard to this. Thank you!
Martin
Dr. Martin Pl�derl
Fachbereich Psychologie
Universit�t Salzburg
Hellbrunnerstr. 34
5020 Salzburg
Tel: +0043 - 8044 - 5130
Email: martin.ploederl(a)sbg.ac.at