Hi all, I'm relatively new to SAS and the community, really appreciate the chance for getting help here. Thanks in advance for any help I may get. I am running Proc Logistic to build a logistic regression model, and just found that I got two drastically different c statistic value with or without having the option plots=ROC in the Proc Logistic statement. It seems very confusing to me and I have no idea about the reason. A intense Google search didn't find anything. My code is like this Proc Logistic data=mydata desc; weight wgt; model target=&vars; ouput out=myout p=p; run; The c statistic in the result is 0.552. Percent Concordant is 10.3, and Percent Tied is 89.6. Gamma is 0.996. Then I turned plots=ROC on, and my code now looks like this. Proc Logistic data=mydata desc plots=ROC; weight wgt; model target=&vars; ouput out=myout p=p; run; The c statistic becomes 0.929, Percent Concordant is 92.4, Percent Tied is 0.9, and Gamma is 0.865. They all are very different from the previous set of values. Anyone can share your insight into this? Why adding plots=ROC changes the value of results? thanks, Richard
... View more