Dear R Help list,

My question is regarding extracting the standard error or Z-score from a
cph or coxph call. My Cox model is: -

modz=cph(Surv(TSURV,STATUS)~RAGE+DAGE+REG_WTIME_M+CLD_ISCH+POLY_VS,
data=kidneyT,method="breslow", x=T, y=T)

I've used names(modz) but can't see anything that will let me extract
the Z scores for each coefficient or the standard errors in the same way
one can use coef (modz).

I need to get either the se or Zscore as I am hoping to be able to use
the Zscore within a statistic function used in censboot. I wish to find
the proportion of times each of the variables in the cox model are
significant out of the R=1000 bootstrap resamples.

My current function for us with the bootstrap only gives me the
coefficients: - 

func=function(kidneyT,indices)
{

kidneyT=kidneyT[indices,]
modz=coxph(Surv(TSURV,STATUS)~RAGE+DAGE+REG_WTIME_M+CLD_ISCH+POLY_VS,dat
a=kidneyT,method="breslow")

coefficients(modz)

}


I would like to be able to modify the following code so modz.cens.boot$t
below gives me an array of the Z-scores for each variable and each
resample - not the coefficients

modz.cens.boot=censboot(kidneyT, func,R=1000,sim="ordinary")
modz.cens.boot


I hope this is clear enough? I'm still getting to terms with the
Bootstrap, having only just started trying to use it a few days ago.

Any help on this would clear a massive headache for me as I've been
going around in circles for hours and hours on this.

Thx 

DaveL





Click to find information on your credit score and your credit report.
<http://tagline.bidsystem.com/fc/Ioyw36XIe1IYw28KqOSu66l6ED7AsGYWlz4EWyK
N5OTcqKjQM8gfiW/> 



<span id=m2wTl><p><font face="Arial, Helvetica, sans-serif" size="2" style="font-size:13.5px">_______________________________________________________________<BR>Get the Free email that has everyone talking at <a href=http://www.mail2world.com target=new>http://www.mail2world.com</a><br>  <font color=#999999>Unlimited Email Storage &#150; POP3 &#150; Calendar &#150; SMS &#150; Translator &#150; Much More!</font></font></span>
	[[alternative HTML version deleted]]

