Wennberg was the founding editor of The Dartmouth Atlas of Health Care, which examines the patterns of medical resource intensity and use in the United States.
In a 2002 Health Affairs article, Wennberg proposed a Medicare reform plan based on reducing unwarranted regional variations in spending by the program.
[4] In the latest Dartmouth Atlas, Wennberg and colleagues state that "the Medicare system could reduce spending by at least 30 percent while improving the medical care of the most severely ill Americans.
In the first part of a two-part article, Wennberg and his coauthors urge the Centers for Medicare and Medicaid Services (CMS) to use its pay-for-performance program to ensure that patients are both informed and empowered to choose appropriate discretionary treatments.
[6] In 1967, Wennberg worked with the Regional Medical Program created with a $350,000 grant from President Lyndon Johnson and began analyzing Medicare data to determine how well hospitals and doctors were performing.
The basic premise—that medicine was driven by science and by physicians capable of making clinical decisions based on well-established fact and theory—was simply incompatible with the data we saw.
"[This quote needs a citation] Albert Mulley, a physician at Massachusetts General Hospital, had been conducting research with Wennberg of Dartmouth by the Informed Medical Decisions Foundation.
But over the past 20 years, work done by Dartmouth's Wennberg and Elliott Fisher has forced U.S. health care leaders to acknowledge that this simply isn’t true.