Date: Fri, 7 Nov 2008 02:02:56 -0800
Reply-To: "cat.." <cat.b41@GMAIL.COM>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: "cat.." <cat.b41@GMAIL.COM>
Subject: Stepwise selection in proc logistic
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I'm trying to understand in detail, step by step, how the stepwise
selection process works and I study the following SAS example:
But I'm confused about one thing: The first set of covariates is: cell
smear infil li blast temp.
At step 0, only the intercept is entered, and, before entering the
step 1, a table is displayed that shows the analysis of effects
eligible for entry. Which includes, at step 0: cell smear infil li
Is this table supposed to display the Chi-square score of significance
of the estimate of each effect when fitting the model remis = cell
smear infil li blast temp ?
In that case, why does the code
proc logistic data=Remission descending outest=betas covout;
model remiss=cell smear infil li blast temp;
yield chi-square scores that are completely different !!
Thanks for your help.