Re: [R] Difference between R and SAS in Corcordance index in ordinal logistic regression

Dear Dr Harrell, About the mean probabilities, I was refering to the ones computed with the command predict(...,type="mean"). I tried to set the binwidth in SAS to 0.0001 as you suggested. After having negated the predictors, I found a C index of 0.968, which is exactly the same that rcorr.cen

Re: [R] Difference between R and SAS in Corcordance index in ordinal logistic regression

Dear Dr Harrell, Thank you very much for your answer. Actually I also tried to found the C index by hand on these data using the mean probabilities and I found 0.968, as you just showed. I understand now why I had a slight difference with the outpout of lrm. I am thus convinced that this result