subsequent editions of the Atlas have revealed astounding geographical variations in how medical resources are distributed and used—for example, a 33-fold difference in the rate of lumpectomies and mastectomies from one region to another. "That's simply staggering," Dr. Jack Lord, then vice president of the American Hospital Association, told the New York Times.

Soon, mentions in the Times and other major media outlets were all in a day's work for Wennberg and his CECS colleagues. One of his oft-quoted collaborators is Dr. Elliott Fisher, who became the lead researcher on studies that revealed, virtually beyond doubt, that in markets where patients receive more aggressive, intensive care, outcomes are no better. And all too often they are actually worse.

Over time, it became clear that the supply of beds and specialists was not the only factor driving "more care." Wennberg realized that what he had called the "practice style factor" in his 1984 article was also important—especially when it came to elective surgeries. In some areas, physicians favored more aggressive medicine. In these markets, patients with heart problems, for example, would be more likely to have cardiac bypasses and less likely to be encouraged to try drug therapy or lifestyle changes. And patients diagnosed with early-stage prostate cancer would be more likely to undergo surgery or radiation therapy and less likely to opt for "watchful waiting."

Yet Wennberg recognized that, when it comes to elective surgery, there is by definition no right answer. That's why it's "elective." And that means patients should consider their own priorities regarding risks and benefits, not just accept the doctor's presumption of them. In 1989, Wennberg had cofounded the Foundation for Informed Medical Decision Making, a nonprofit organization that has

The Dartmouth Atlas and studies based on its data continue to make headlines in top media outlets nationwide—and today are fodder for health-care bloggers.

In a 1984 paper in Health Affairs, Wennberg went on to demonstrate, once again, that the supply of hospital beds and specialists in a particular market often determines how medicine is practiced—even at the most prestigious medical centers.

blazed the trail for what's come to be called "shared decision-making." (For insight into DHMC's first-in-the-nation Center for Shared Decision Making, see "Making Choice an Option" in the Fall 2007 issue of Dartmouth Medicine.) The concept's presumption is that when medical science is ambiguous, patients deserve a chance to participate in the treatment choice, based on a frank appraisal of what is—and is not—known.

Discussion, not dogma
CECS has also aimed to give clinicians a chance to discuss what they are doing—and, more importantly, why. "Medical education tends to be dogmatic," Wennberg says. "The chief of medicine has the last word on medical truth. In ward rounds, any debate is squashed by [saying], 'It's medically appropriate to do it this way.'"

By contrast, he continues, "in the basic sciences, you have discussion and debate. Why not in medicine? We need to be continually evaluating what we are doing over time. 'Why are we doing this?What is the evidence that it is working?'We need to fund the evaluative sciences," Wennberg declares. For a moment, he sounds angry, because he knows that those who profit from unproven, expensive, and often ineffective treatments—device manufacturers, drug companies, even some doctors—have for years opposed head-to-head comparisons of one treatment against another. He believes academic medical centers should be on the front lines of the fight. "They need to advocate for independent comparative effectiveness research," he says. "It is the only way to make clinical medicine a more robust science."

This is exactly what CECS aimed to do for nearly 20 years under Wennberg's leadership. He is still, at age 73, active in its work. And he still holds DMS's Peggy Y. Thomson Professorship in the Evaluative Clinical Sciences—the nation's first endowed chair devoted to outcomes research. But he has, as of July 2007, stepped down as director and passed that torch to his colleague Jim Weinstein.

In the early 1990s, Weinstein was a tenured professor of orthopaedics at the University of Iowa. He had just been asked to codirect Iowa's office of outcomes, evaluation, and management.

"I didn't feel that qualified,"Weinstein recalls. "As it happened, I had attended a meeting on outcomes in San Antonio where Jack had been one of the speakers, and at the time, Jack said, 'You ought to come out to Dartmouth. We have new programs you should see.'"

Weinstein took him up on the suggestion, deciding in 1994 to spend a sabbatical year getting a master's degree at CECS. He was especially impressed with the