[R] test of hazard ratios

[Spencer Graves]

	  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.

	  If you don't see how to make this work, PLEASE do read the posting 
guide! "http://www.R-project.org/posting-guide.html".  It might help you 
find a better answer.  Failing that, if you submit another post after 
following the process described therein, it should increase the chances 
that you will get a useful reply.

	  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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