Harvard Health Letter

Too much of a good thing

Dartmouth researchers find that patterns of medical care vary widely — and that more services don't mean better outcomes.

An article in The New England Journal of Medicine in 2007 about the cancer risk associated with the radiation from CT scans got a good deal of attention. In the measured, passive voice so often used in medical journal articles ("...there is a strong case to be made..."), the team of authors from Columbia University Medical Center suggested that many of the potentially cancer-causing scans are probably unnecessary and done for the wrong reasons — out of fear of lawsuits and inadvertent duplication.

Regional variations

The evidence that CT scans are likely being overused couldn't have come as much of a surprise to an enterprising group of researchers at Dartmouth Medical School. Led by Dr. John Wennberg, the Dartmouth group has shown that there are large variations in the way medicine is practiced in the United States that don't have anything to do with either patients' needs or the latest research. Shannon Brownlee painted a vivid portrait of Wennberg and his work in her 2007 book Overtreated: Why Too Much Medicine is Making Us Sicker and Poorer, a compelling account of the expensive flaws of the American health care system.

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