> For example, if you had a study which compared moderate drinkers to non-drinkers, but not carve out "cannot drink due to other medication" from the second gro

> For example, if you had a study which compared moderate drinkers to non-drinkers, but not carve out "cannot drink due to other medication" from the second group, you get a more discriminatory result from the study. Yeah. From what I remember about these studies is that people who used to smoke but don't anymore actually have higher risk of contracting severe Covid. This is easily explained by the fact that many people who quit smoking do so due to health reasons (which in turn are the cause for higher risk of Covid).