Scientific Medicine

David Eddy, MD, PhD, a healthcare economist, says the problem with American medicine "that physicians don't know what they're doing."

Many clinical decisions made by physicians appear to be arbitrary, uncertain and variable. Reams of research point to the same finding: physicians looking at the same thing will disagree with each other, or even with themselves, from 10 percent to 50 percent of the time during virtually every aspect of the medical-care process—from taking a medical history to doing a physical examination, reading a laboratory test, performing a pathological diagnosis and recommending a treatment. Physician judgment is highly variable.

Here is what Eddy has found in his research. Give a group of cardiologists high-quality coronary angiograms (a type of radiograph or x-ray) of typical patients and they will disagree about the diagnosis for about half of the patients. They will disagree with themselves on two successive readings of the same angiograms up to one-third of the time. Ask a group of experts to estimate the effect of colon-cancer screening on colon-cancer mortality and answers will range from five percent to 95 percent. . . .

Give surgeons a written description of a surgical problem, and half of the group will recommend surgery, while the other half will not. Survey them again two years later and as many as 40 percent of the same surgeons will disagree with their previous opinions and change their recommendations. Research studies back up all of these findings, according to Eddy. . . .

Most physicians practice in a virtually data-free environment, devoid of feedback on the correctness of their practice. They know very little about the quality and outcomes of their diagnosis and treatment decisions. And without data indicating that they should change what they're doing, physicians continue doing what they've been doing all along.

And yet as I write Republicans in Congress are trying to eliminate funding for developing medical best practice guidelines.