They actually do compare against a control group. This is the study that is being referenced. https://bmjmedicine.bmj.com/content/5/1/e002150 https://bmjmedici

They actually do compare against a control group. This is the study that is being referenced. https://bmjmedicine.bmj.com/content/5/1/e002150 https://bmjmedicine.bmj.com/content/5/1/e002150 The data on the results section shows almost parity between the control group and participants who discontinued for 2 years. Note that while it is a well conducted study at the US VA with 300,000+ patients, it is not a randomized study so fully eliminating confounding variables and reverse causality is hard.