LISTSERV at the University of Georgia
Menubar Imagemap
Home Browse Manage Request Manuals Register
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (January 2008)Back to main SPSSX-L pageJoin or leave SPSSX-L (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Tue, 29 Jan 2008 09:16:41 -0600
Reply-To:     "Reutter, Alex" <areutter@spss.com>
Sender:       "SPSSX(r) Discussion" <SPSSX-L@LISTSERV.UGA.EDU>
From:         "Reutter, Alex" <areutter@spss.com>
Subject:      Re: Conditional logistic problems
In-Reply-To:  A<002701c861ea$4adf5150$2845cd80@ssw.buffalo.edu>
Content-Type: text/plain; charset="us-ascii"

Gene,

This doesn't directly help your problems with COXREG, but if the dataset is matched 1:1 and not 1:many, you can alternatively use Multinomial Logistic Regression (NOMREG). There's an example in Marija Norusis's Advanced Statistical Procedures Companion and another in the online help (Help>Case Studies, then Regression Models>Multinomial Logistic).

Cheers, Alex

-----Original Message----- From: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] On Behalf Of Gene Maguin Sent: Monday, January 28, 2008 2:14 PM To: SPSSX-L@LISTSERV.UGA.EDU Subject: Conditional logistic problems

All,

I have been working with another list subscriber who has a matched (1:1) dataset and is trying to analyze relationships between variables using conditional logistic regression (CLR). I have no experience with this type of model. However, I did find a posting by Marta (shown below) as well as several discussion sites. Since spss logistic won't do a conditinal analysis, the trick is to use the coxreg procedure to do so. I believe I have faithfully followed Marta's directions but am getting no results and so, there is something I don't understand. Per Marta's posting, I have

COXREG ftime /STATUS=outcome(1) /STRATA=pair /METHOD=ENTER x /PRINT=CI(95).

Where Ftime is the survival time variable computed such that ftime=outcome+1. outcome is the case-control variable with 0=control, 1=case. Pair is the strata variable, 161 pairs. X is the IV.

My case processing box shows

Case Processing Summary N Percent Cases available in analysis Event(a) 161 50.0% Censored 0 .0% Total 161 50.0% Cases dropped Cases with missing values 0 .0% Cases with negative time 0 .0% Censored cases before the earliest event in a stratum 161 50.0% Total 322 100.0% a Dependent Variable: ftime

Variables in the Equation(b) Wald df Sig. X . 0(a) . aDegree of freedom reduced because of constant or linearly dependent covariates bConstant or Linearly Dependent Covariates S = Stratum effect. x = .5093 + S;

If somebody can educate me about what I'm missing or need to look at, I'd greatly appreciate it.

Thanks, Gene Maguin

===================== To manage your subscription to SPSSX-L, send a message to LISTSERV@LISTSERV.UGA.EDU (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD

===================== To manage your subscription to SPSSX-L, send a message to LISTSERV@LISTSERV.UGA.EDU (not to SPSSX-L), with no body text except the command. To leave the list, send the command SIGNOFF SPSSX-L For a list of commands to manage subscriptions, send the command INFO REFCARD


Back to: Top of message | Previous page | Main SPSSX-L page