Subha P. T.
2012-Feb-17 07:10 UTC
[R] stepwise selection for conditional logistic regression
Hi, Is there any function available to do stepwise selection of variables in Conditional(matched) logistic regression( clogit)? step, stepwise etc are failing in case of conditional logistic regression. Please help. Thanks P.T. Subha [[alternative HTML version deleted]]
Weidong Gu
2012-Feb-17 14:40 UTC
[R] stepwise selection for conditional logistic regression
stepAIC works for an object of clogit. Weidong Gu On Fri, Feb 17, 2012 at 2:10 AM, Subha P. T. <subha_iss at yahoo.com> wrote:> > > ?Hi, > > Is there any function available to do stepwise selection of variables in Conditional(matched) logistic regression( clogit)? step, stepwise ?etc are failing in case of conditional logistic regression. Please help. > > Thanks > > P.T. Subha > ? ? ? ?[[alternative HTML version deleted]] > > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >
David Winsemius
2012-Feb-17 15:41 UTC
[R] stepwise selection for conditional logistic regression
On Feb 17, 2012, at 2:10 AM, Subha P. T. wrote:> > > Hi, > > Is there any function available to do stepwise selection of > variables in Conditional(matched) logistic regression( clogit)? > step, stepwise etc are failing in case of conditional logistic > regression."Failing" is open to a variety of interpretation. Can you offer an example and describe what you mean or quote an error message? I tested the advice in this posting from C. Berry with the example in ? clogit and got appropriate results: http://finzi.psych.upenn.edu/Rhelp10/2010-January/226165.html> Please help. >Stepwise procedures are supported somewhat grudgingly on r-help. You ought to read some of the critical comments about stepwise procedures in the Archives: http://search.r-project.org/cgi-bin/namazu.cgi?query=stepwise+significance&max=100&result=normal&sort=score&idxname=functions&idxname=Rhelp08&idxname=Rhelp10&idxname=Rhelp02 Another search strategy might be "stepwise Harrell". -- David Winsemius, MD West Hartford, CT
Frank Harrell
2012-Feb-22 13:22 UTC
[R] stepwise selection for conditional logistic regression
Stepwise variable selection is an invalid statistical method. Who or which book recommended it? Frank Subha P. T. wrote> > ?Hi, > > Is there any function available to do stepwise selection of variables in > Conditional(matched) logistic regression( clogit)? step, stepwise ?etc are > failing in case of conditional logistic regression. Please help.? > > Thanks > > P.T. Subha > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@ mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >----- Frank Harrell Department of Biostatistics, Vanderbilt University -- View this message in context: http://r.789695.n4.nabble.com/stepwise-selection-for-conditional-logistic-regression-tp4396607p4410260.html Sent from the R help mailing list archive at Nabble.com.