This is also known as confounding by indication, and is something the pharmacoepidemiology field contents with a lot. And it shows up all the time in things li

This is also known as confounding by indication, and is something the pharmacoepidemiology field contents with a lot. And it shows up all the time in things like the Consumer Reports hospital rankings and the like, where hospitals with particularly uncomplicated patient populations come off looking like they're the best hospitals.