Thank you Frank for your prompt reply
You're definitely right, it seems that comparing rank concordance is a quite
inefficient way to test the predictive power of a covariable. Thus LR test
works better.
Stefano
On 4/21/06, Frank E Harrell Jr [EMAIL PROTECTED] wrote:
Stefano Mazzuco wrote:
Stefano Mazzuco wrote:
Hi R-users,
I'm having some problems in using the Hmisc package.
I'm estimating a cox ph model and want to test whether the drop in
concordance index due to omitting one covariate is significant. I think (but
I'm not sure) here are two ways to do that:
1) predict
