Doing a Cox-Regression in R and SPSS
On 11 Mar 2001, at 7:51, Prof Brian D Ripley wrote:
On Sun, 11 Mar 2001, Bernd Weiss wrote:
computing a Cox proportional hazards model in SPSS 9.0 and R 1.2.2 produces different results for beta-coefficient.
[...]
method: a character string specifying the method for tie
handling.
If there are no tied death times all the methods
are equivalent. Nearly all Cox regression programs
use the Breslow method by default, but not this
one. The Efron approximation is used as the
default here, as it is much more accurate when
dealing with tied death times, and is as efficient
computationally. The exact method computes the
exact partial likelihood, which is equivalent to a
conditional logistic model. If there are a large
number of ties the computational time will be
excessive.
[...] <coxph(Surv(t,s)~x, method="breslow", data=coxdata)> works fine. Thanks for your help. Bernd -- Bernd Wei? (bernd.weiss at epost.de) PGP Key ID: 0x4117206F PGP FP: 08B2 09CD 7192 526D 93FD 2070 53DB 7C4F 4117 206F www.pgpi.org -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._