I'm trying to run a Response Surface Analysis in SAS, but this is only possible with a continuous outcome, whereas my outcome variable is binary. I got the advice to first run a logistic regression and save the predicted probabilities. I could then run the Response Surface Analysis with the predicted probabilities as the continuous outcome variable.
However, the significance test of the Response Surface Analysis do not make any sense and my R² is extremely high. Someone else told me that I should plot a ROC curve and look at the AUC, but I have the feeling that there is more going on then simply adjusting my threshold. Unfortunately I can't seem to find any information on this subject online. Does somebody have any idea how to properly use the predicted probabilities of a logistic regression as the outcome variable of a linear regression?
Best wishes, Alexander