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]] ______________________________________________ Rfirstname.lastname@example.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.