Date:         Mon, 2 Oct 2006 11:27:28 -0400
Reply-To:     Scott Czepiel <sczepiel@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Scott Czepiel <sczepiel@GMAIL.COM>
Subject:      Re: logistic regression
In-Reply-To:  <2CA33C37A5A1FA4E8B3DD50B36E11C6F3F1FB1@nnmc-exch4.nnmc.med.navy.mil>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

In CATMOD and LOGISTIC, the default is for the largest value to be the
omitted value.  Thus, for a binary dependent variable, this will model the
probability of occurence of the smallest value.  For this reason, it is
common to see binary variables in SAS coded as 1=yes, 2=no (rather than
1/0).

On 10/2/06, Cecilia Kim <CHKim@bethesda.med.navy.mil> wrote:
>
> It means that you're predicting the probability of a nonevent.
> You need to use DESCENDING option to change this to predicting the
> probability of an event (dep_var = 1).
> Cecilia
>
> Cecilia H. Kim, MPH
> Nurse Researcher
> Comprehensive Colon Cancer Center Initiative
> National Naval Medical Center
> 8901 Wisconsin Avenue
> Bethesda, MD 20889
> Office (301) 319-5015
> PIN 1063751
> -----Original Message-----
> From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of Jing
> Quan
> Sent: Monday, October 02, 2006 10:47 AM
> To: SAS-L@LISTSERV.UGA.EDU
> Subject: logistic regression
>
> In an SAS output, I see  "Probability modeled is dep_var=0." What does
> it mean? The reason I'm a little confused is that I understand the
> estimation is done for prob (dep_var=1).
>
> Thanks for your help.
>
>
> Regards,
>
> Jing "Jim" Quan
> Dept of Info and Decision Sciences
> Salisbury University
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