Study on Mayo Clinic site contradicts some standard treatments
By Andis Robeznieks
The latest is not always the greatest in medical treatments, according to a study posted on the Mayo Clinic Proceedings website. It reviewed the findings of more than 1,300 previously published reports on medical practices.
Clinical areas where current practice standards were contradicted by published studies include the drug aprotinin used in cardiac surgery, the use of hormone therapy for postmenopausal women, the use of pulmonary artery catheters, the recommended glycemic targets for diabetics, and the use of arthroscopic surgery of the knee for osteoarthritis.
“We expect that new medical practices gain popularity over older standards of care on the basis of robust evidence indicating clinical superiority or noninferiority with alternative benefits (e.g., easier administration and fewer adverse effects),” wrote the study's authors, who included researchers from the National Cancer Institute, Yale University and other institutions. “The history of medicine, however, reveals numerous exceptions to this rule.”
They note how the use of stents became a multibillion-dollar-a-year industry before it was shown that medical management was just as effective for patients with stable coronary artery disease.
Their review, which involved reports published in the New England Journal of Medicine between 2001 and 2010, identified 981 studies involving a new practice and 363 testing established practices. They found 756 articles in which a new practice had better results than the current standard of care, and 165 where a new practice failed to improve on the current standard. “Back to the drawing board,” the authors wrote.
Of the 363 studies testing a standard practice, 40.2% reversed the standard, 38% confirmed it and 27.3% were inconclusive. Some current standards were reversed by more than one article. Of the 146 studies contradicting the value of current medical practice standards, 128 individual practices were identified.
“When medical practices are instituted in error, most often on the basis of premature, inadequate, biased and conflicted evidence, the costs to society and the medical system are immense,” the authors concluded. “Our position is in contrast to efforts to lower standards for device and drug approval, which further erodes the value of the regulatory process.”
In an accompanying editorial, Dr. John Ioannidis, of Stanford University School of Medicine's Prevention Research Center, Palo Alto, Calif., warned that articles published in the New England Journal of Medicine might be “susceptible to publication and selective outcome reporting bias,” but concluded that the review offered valuable insight.
“Despite better laboratory science, fascinating technology, and theoretically mature designs after 65 years of randomized trials, ineffective, harmful, expensive medical practices are being introduced more frequently now than at any other time in the history of medicine,” Ioannidis wrote. “Under the current mode of evidence collection, most of these new practices may never be challenged.”
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