I have a dependent variable "response" as binary 1 = response, 0 = no response (for surgery). I have an independent variable of a certain measurement in degrees (continuous/ordered variable).
So I have the idea of calculating a cut-off point for this radiologic measurement, seeing as it's strongly associated to my outcome. However, doing a roctab, the graph looks like this:
Am I doing something wrong here? That ROC curve is terrible, worse than a coinflip, despite the data looking so good before?