Hi SAS communities, I have the following challenge: I have a logistical regression model including a binary outcome and some categorical and continuous covariates. The logistical regression model achieved a c-statistic (or area under the ROC curve) of 0.94. I have then used bootstrapping (unrestricted random sampling) to create 50 data sets (later I will do 1000) put together in one data set, sorted by replicate number (1-50). Then I run the proc logistic on the large data set, using a 'by replicate' statement. In the SAS results window I how have 50 separate c-statistics. Which leads me to the question: How do I combine the 50 separate c-statistics in the results window, so that I can obtain a single median c-statistics for all the bootstrapped data sets? Preferably also with confidence limits... I have attached the SAS code in a word file. Best, Sebastian Wiberg, MD
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