Re: [R] test of hazard ratios

From: Spencer Graves <>
Date: Wed 29 Jun 2005 - 07:24:43 EST

          Can you fit a single model that includes the two classifiers from which the model with one classifier could be obtained as a special case?   If yes (and if neither parameter was at a boundary crudely similar to a zero variance component in "lme"), then you could use the theory that 2*ln(likelihood ratio) is approximately chi-square. For many capabilities in R, this is implemented as a function anova(fit2, fit1) where fit2 and fit1 are the results of fitting the general and the specialized models.

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          spencer graves

Steve Adams wrote:

> Hi,
> Is there a R test available that tests whether 2
> hazard ratios obtained from Cox regressions on the
> same patient sample by 2 different classifiers are
> significantly different?
> Thanks
> Steve
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> PLEASE do read the posting guide!

Spencer Graves, PhD
Senior Development Engineer
PDF Solutions, Inc.
333 West San Carlos Street Suite 700
San Jose, CA 95110, USA <>
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Received on Wed Jun 29 07:35:47 2005

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