Hypothetical drugs. Hypothetical studies. Ten years use. Relative risk reduction compared to absolute risk reduction at the end of the ten year study. Assuming little to no side effects from either one.

Drug A. 10,000 participants in the study. Placebo group 5,000 people die. Drug A. group 2,500 people die. 50% relative risk reduction. Absolute risk reduction 25%. (have to treat 4 people to save one additional life)

Drug B.  10,000 participants in the study. Placebo group 2 people die. Drug B. group 1 person dies. 50% relative risk reduction. Absolute risk reduction one tenth of 1%. (have to treat 10,000 people to save one additional life).

Would you take drug A for ten years.? I sure would, Unless it is a million dollars a year cost or some other non-medical reason not to. One in four people life lengthened (mortality among humans is eventually always 100%).

Would you take drug B for ten years.? I might if I was very sure there were absolutely no bad side effects.  But probably not. Have to treat 10,000 people for ten years to save one life. It would have to be almost free of cost and absolutely sure it was not going to harm me in any way (and that is never the case even with things as simple as aspirin or Tylenol).

The TV drug company advertisements would advertise BOTH with great fanfare "50% RISK REDUCTION of death!". And they are both correct and are not false advertising. Yet the absolute risk reduction is off the charts amazing on Drug A. and probably within statistical distance of being zero or meaningless on the other. Yet THEY ARE BOTH 50% REDUCTION OF DEATH! Relatively speaking. In absolute terms not at all the same. One in four vs one in then thousand.

Drug companies advertise using relative risk improvement figures. In some cases, when looking at the actual studies, it is almost meaningless. Almost no one cooperated and died on either the drug group OR the placebo. But the relative difference is big enough to make the TV ads sell the drug and the drug company reps promotion to doctors are convincing. Or they use some other criteria, like reducing heart attacks (even though not improving life length). They choose what sounds the best and they can find statistical significance.

Drug companies use relative risk to sell drugs. Oddly enough (or maybe not so odd), they use absolute risk when talking about side effects! Hmmmmm. Wonder why?

Taking drug A above is a no brainer. Taking Drug B above is almost meaningless. Yet they BOTH can advertise 50% reduction in death (or whatever criteria they decided to make as the outcome - drug companies use heart problems as the outcome because the outcomes of most of the studies don't show statins any help in making people live longer).

Someone check my math. I'm not all that smart.