Medical expertise

Previously I posted on the myth of expertise. Experts in many fields often perform no better than chance when making predictions.

This Businessweek article claims that no more than 25% of medical recommendations are supported by statistical data. Most of it is done by tradition, or according the doctor's intuition. The article profiles David Eddy, a heart surgeon who spent some time learning mathematics and earned a PhD in operations research. He revolutionized the field by pushing for "evidence-based" medicine. What is amazing to me is that this took so long and happened so recently.

...Even today, with a high-tech health-care system that costs the nation $2 trillion a year, there is little or no evidence that many widely used treatments and procedures actually work better than various cheaper alternatives.

This judgment pertains to a shocking number of conditions or diseases, from cardiovascular woes to back pain to prostate cancer. During his long and controversial career proving that the practice of medicine is more guesswork than science, Eddy has repeatedly punctured cherished physician myths. He showed, for instance, that the annual chest X-ray was worthless, over the objections of doctors who made money off the regular visit. He proved that doctors had little clue about the success rate of procedures such as surgery for enlarged prostates. He traced one common practice -- preventing women from giving birth vaginally if they had previously had a cesarean -- to the recommendation of one lone doctor. Indeed, when he began taking on medicine's sacred cows, Eddy liked to cite a figure that only 15% of what doctors did was backed by hard evidence.

A great many doctors and health-care quality experts have come to endorse Eddy's critique. And while there has been progress in recent years, most of these physicians say the portion of medicine that has been proven effective is still outrageously low -- in the range of 20% to 25%. "We don't have the evidence [that treatments work], and we are not investing very much in getting the evidence," says Dr. Stephen C. Schoenbaum, executive vice-president of the Commonwealth Fund and former president of Harvard Pilgrim Health Care Inc. "Clearly, there is a lot in medicine we don't have definitive answers to," adds Dr. I. Steven Udvarhelyi, senior vice-president and chief medical officer at Pennsylvania's Independence Blue Cross.

What's required is a revolution called "evidence-based medicine," says Eddy, a heart surgeon turned mathematician and health-care economist. Tall, lean, and fit at 64, Eddy has the athletic stride and catlike reflexes of the ace rock climber he still is. He also exhibits the competitive drive of someone who once obsessively recorded his time on every training run, and who still likes to be first on a brisk walk up a hill near his home in Aspen, Colo. In his career, he has never been afraid to take a difficult path or an unpopular stand. "Evidence-based" is a term he coined in the early 1980s, and it has since become a rallying cry among medical reformers. The goal of this movement is to pierce the fog that envelops the practice of medicine -- a state of ignorance for which doctors cannot really be blamed. "The limitation is the human mind," Eddy says. Without extensive information on the outcomes of treatments, it's fiendishly difficult to know the best approach for care.

The human brain, Eddy explains, needs help to make sense of patients who have combinations of diseases, and of the complex probabilities involved in each. To provide that assistance, Eddy has spent the past 10 years leading a team to develop the computer model that helped him crack the diabetes puzzle. Dubbed Archimedes, this program seeks to mimic in equations the actual biology of the body, and make treatment recommendations as well as figure out what each approach costs. It is at least 10 times "better than the model we use now, which is called thinking," says Dr. Richard Kahn, chief scientific officer at the American Diabetes Assn.

WASTED RESOURCES

Can one computer program offset all the ill-advised treatment options for a whole range of different diseases? The milestones in Eddy's long personal crusade highlight the looming challenges, and may offer a sliver of hope. Coming from a family of four generations of doctors, Eddy went to medical school "because I didn't know what else to do," he confesses. As a resident at Stanford Medical Center in the 1970s, he picked cardiac surgery because "it was the biggest hill -- the glamour field."

But he soon became troubled. He began to ask if there was actual evidence to support what doctors were doing. The answer, he was surprised to hear, was no. Doctors decided whether or not to put a patient in intensive care or use a combination of drugs based on their best judgment and on rules and traditions handed down over the years, as opposed to real scientific proof. These rules and judgments weren't necessarily right. "I concluded that medicine was making decisions with an entirely different method from what we would call rational," says Eddy.

About the same time, the young resident discovered the beauty of mathematics, and its promise of answering medical questions. In just a couple of days, he devoured a calculus textbook (now framed on a shelf in his beautifully appointed home and office), then blasted through the books for a two-year math course in a couple of months. Next, he persuaded Stanford to accept him in a mathematically intense PhD program in the Engineering-Economics Systems Dept. "Dave came in -- just this amazing guy," recalls Richard Smallwood, then a Stanford professor. "He had decided he wanted to spend the rest of his life bringing logic and rationality to the medical system, but said he didn't have the math. I said: 'Why not just take it?' So he went out and aced all those math courses."

To augment his wife's earnings while getting his PhD, Eddy landed a job at Xerox Corp.'s (XRX ) legendary Palo Alto Research Center. "They hired weird people," he says. "Here was a heart surgeon doing math. That was weird enough."

Eddy used his newfound math skills to model cancer screening. His Stanford PhD thesis made front-page news in 1980 by overturning the guidelines of the time. It showed that annual chest X-rays and yearly Pap smears for women at low risk of cervical cancer were a waste of resources, and it won the most prestigious award in the field of operations research, the Frederick W. Lanchester prize. Based on his results, the American Cancer Society changed its guidelines. "He's smart as hell, with a towering clarity of thought," says Stanford health economist Allan Enthoven.

Dr. William H. Herman, director of the Michigan Diabetes Research & Training Center, has a competing computer model that clashes with Eddy's. Nonetheless, he says, "Dr. Eddy is one of my heroes. He's sort of the father of health economics -- and he might be right."

..."At each meeting I would do the same exercise," he says. He would ask doctors to think of a typical patient and typical treatment, then write down the results of that treatment. For urologists, for instance, what were the chances that a man with an enlarged prostate could urinate normally after having corrective surgery? Eddy then asked the society's president to read the predictions.

The results were startling. The predictions of success invariably ranged from 0% to 100%, with no clear pattern. "All the doctors were trying to estimate the same thing -- and they all gave different numbers," he says. "I've spent 25 years proving that what we lovingly call clinical judgment is woefully outmatched by the complexities of medicine."