They were testing what happens when you stop taking Ozempic compared to what happens when you don't stop taking it, and also what happens when you start taking it again.

Assembling a control group of people who have never taken Ozempic could be difficult. How do you control for the fact that people not on Ozempic are less likely to need Ozempic? You'd need to figure out some criteria by which to include and exclude patients before sorting by whether they take Ozempic or not, so you'd have a smaller sample size of people who are taking Ozempic.

Best not to allow scope creep.