Date: Tue, 23 Nov 2004 09:06:38 -0800
Reply-To: Neerav <neerav_monga@CAMH.NET>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: Neerav <neerav_monga@CAMH.NET>
Subject: Re: Interpreting PROC LOGISTIC output: Odds Ratio Estimates
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As Peter said, the odds ratio explains the association between and an
IV with a DV. It is as its name suggests, a ratio of 2 odds. So for
example, if you're looking at smoking status (yes or no) predicting low
birthweight baby (yes or no), with 'no' being the reference category,
an odds ratio of 2.0 for example would say: The odds of a smoker having
a low birthweight baby is 2.0 times the odds of a non-smoker having a
low birthweight baby. This is the categorical case.
As for continuous, it is the same interpretation except you're talking
about an odds ratio for a one unit change in your predictor (eg. age).
Again , its a ratio of the odds of one event occuring to the odds of
another event (smoker vs non-smoker in my example). Hope that helps,
if you need more information, you can look at "Categorical data
anlaysis using the SAS system", by Stokes, Davis & Koch. A very good