As usual, without double blind studies, this is playing with fire… maybe the people taking it have better health because of the extra exercise that goes with an active sex life.
But I would be surprised if there were not a measurable increase in health markers for men who take Cialis. Pretty much any drug that reduces blood pressure is going to have a positive effect on longevity for the average male population (but not the sub-population who have low blood pressure).
That was immediately my thought as well, the population of men who seek out ED medications have to be very distinctly different than the population of men in general.
Thus this very well might be a yardstick, not an actual benefit.