Re: [R] NRI reclassification table improveProb Cox

2012-12-24 Thread Frank Harrell
There are several issues. First the Cox model is not for a binary outcome. It is for a time-to-event outcome whose status (event vs. censored) is binary. Second, split-sample validation does not work well with n < 2 in the combined sample. Third, reclassification tables are not used to vali

Re: [R] NRI reclassification table improveProb Cox

2012-12-21 Thread Frank Harrell
As describe in the Hmisc package's improveProb function, that function is for binary Y. And it's best to use category-free methods. Frank Petergodsk wrote > Hi > > I'm new to R. > > Is it possible to use the improveProb function to generate categorybased > NRI using a Cox model? > I believe I