This UCLA study surprised me. Medical researchers should seek to identify those interventions that significantly improve a patient’s survival rate (abstracting from quality of life). The benefits of taking a drug hinge on two parameters. Consider a heart medication. If I take it, how is my survival rate affected? Intuitively, what would my probability of surving as a function of my age be given that I take the drug versus what would it have been had I not taken the drug or taken some other drug? Second, how much do I value this reduction in risk? Medical research seeks to estimate this first parameter. A huge economics literature seeks to measure this second parameter.
Yet, the news release implies that medical research is not pursuing this agenda as it narrowly focuses on how a medicine affects a specific measurable outcome such as blood pressure. Here is a quote; “Patients and doctors care less about whether a medication lowers blood pressure than they do about whether it prevents heart attacks and strokes or decreases the risk of premature death,” said the study’s lead author, Dr. Michael Hochman.” The medical researchers must be implicitly assuming that there is a one to one well known function between elevated blood pressure and nasty outcomes. In this case, knowing how the drug affects blood pressure would be equivalent to knowing how the drug affects “the nasty outcomes” such as elevated death risk. Recall from calculus the Chain Rule, y = f(g(x)). The researchers are studying dg/dx while the patients and clinical doctors care about df/dx.