This feels similar to the thing where "non-drinkers" in studies were composed of "people who had never drank alcohol" and also "recovering alcoholics". I would

This feels similar to the thing where "non-drinkers" in studies were composed of "people who had never drank alcohol" and also "recovering alcoholics". I would imagine a chunk of vapers are people trying to transition from smoking cigarettes and still suffering from some of the ill effects.