These are the findings of a joint study by the Regenstrief Institute for Health Care and the Indiana University School of Medicine, summarized by Clement McDonald [1]. He says that robust scientific conclusions are too sparse to inform fully most of the choices for treatments. Instead, ad hoc rules of thumb, or “heuristics,” must guide them. Since heuristics are inherently context driven, they “should be discussed, criticized, refined, and then

taught. More uniform use of explicit and better heuristics could lead to less practice variation and more efficient medical care.”