According to Vinay Prasad, an oncologist and one of the authors of the Mayo Clinic Proceedings paper, medicine is quick to adopt practices based on shaky evidence but slow to drop them once they’ve been blown up by solid proof. As a young doctor, Prasad had an experience that left him determined to banish ineffective procedures. He was the medical resident on a team caring for a middle-aged woman with stable chest pain. She underwent a stent procedure and suffered a stroke, resulting in brain damage. Prasad, now at the Oregon Health and Sciences University, still winces slightly when he talks about it. University of Chicago professor and physician Adam Cifu had a similar experience. Cifu had spent several years convincing newly postmenopausal patients to go on hormone therapy for heart health—a treatment that at the millennium accounted for 90 million annual prescriptions—only to then see a well-designed trial show no heart benefit and perhaps even a risk of harm. "I had to basically run back all those decisions with women," he says. "And, boy, that really sticks with you, when you have patients saying, 'But I thought you said this was the right thing.'" So he and Prasad coauthored a 2015 book, Ending Medical Reversal, a call to raise the evidence bar for adopting new medical standards. "We have a culture where we reward discovery; we don’t reward replication," Prasad says, referring to the process of retesting initial scientific findings to make sure they’re valid.