Dear R-help,
I am using R-3.3.2 on Windows 10. I teach on a course which has 4 computer
practical sessions related to the development and validation of clinical
prediction models. These are currently written for Stata and I am in the
process of writing them for use in R too (as I far prefer R to Stata!)
I notice that predictions made from a Cox model in Stata are based on
un-centred variables, while they are based on centred variables in R. I am
aware that variable centring is the preferred approach to ensure sensible
predictions from models and thus usually I am pleased that variable centring is
automatically applied within coxph in R. However, for the sake of producing
identical results across the software packages, is there a way to produce
predictions from a Cox model in R without variable centring?
I am using the 'survival' package as follows (for example):
library(survival)
test1 <- list(time=c(4,3,1,1,2,2,3),
status=c(1,1,1,0,1,1,0),
x=c(0,2,1,1,1,0,0),
sex=c(0,0,0,0,1,1,1))
mod1 <- coxph(Surv(time, status) ~ x + sex, test1)
predict(mod1,type="lp")
[This can of course be alternatively obtained from mod1$linear.predictor]
Many thanks for your assistance.
Kind regards,
Laura
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
