Dear Frank
Frank E Harrell Jr <[EMAIL PROTECTED]> wrote:
A few observations.
1. With minimal overfitting, rcorr.cens(predict(fit), Y) gives a good
standard error for Dxy = 2*(C-.5) and bootstrapping isn't very necessary
2. If you bootstrap use the nonparametric bootstrap percentile method
or other methods that constrain the confidence interval to be in [0,1].
3. I don't know why the model would be linear on the two predictors you
are using.
Do you mean using these predictors fitted with spline functions?? I
have read about it in your "Regression Modeling Strategies" but I am
not very sure I understand the use of them. I will read through it
again.
David
Frank
--
Frank E Harrell Jr Professor and Chair School of Medicine
Department of Biostatistics Vanderbilt University
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