UC DAVIS (US)—Use of a largely unproven mammography screening device has increased dramatically since Medicare began covering the cost a decade ago, according to a new study.
Joshua Fenton, assistant professor of family and community medicine at University of California at Davis, examined use of computer-aided detection (CAD) since Congress mandated that Medicare pay for it 10 years ago.
The prevalence of CAD jumped from 5 percent in 2001 to 27 percent in 2003, the most recent year for which data was available. Extra mammography fees for CAD use cost Medicare an estimated $19.5 million in 2003 alone.
Actual costs are probably greater because the device has been associated with higher recall rates and greater use of diagnostic tests such as breast biopsy.
The increase in computer-aided detection use occurred even though “systemic reviews point to uncertainty regarding whether CAD has a clinically important impact on key breast cancer outcomes,” Fenton says.
Details appear in the Archives of Internal Medicine.
Medicare coverage of the device was key to its marketing to hospitals and health-care facilities, which resulted in intense lobbying of Congress for approval of CAD as a covered benefit.
“This illustrates how industry and government interact to determine the course of health-care practice, and it’s not really guided by science,” Fenton says. “This is a case in which expensive technology gets widely adopted in clinical practice before it is proven effective.”
Computer-aided detection software analyzes the mammogram image and marks suspicious areas for radiologists to review. In a previous study of more than 200,000 women who had mammograms, published in the New England Journal of Medicine in 2007, Fenton and colleagues found that CAD produced excessive false-positive results.
His research demonstrated that when it was used, 32 percent more women were recalled for additional tests and 20 percent more women had a breast biopsy, yet use of the software had no clear impact on the early detection of breast cancer.
“This argues that we need a way of evaluating technologies before we put them into practice,” Fenton says. “The government has a huge stake in this. And once the train leaves the station, it’s difficult to call it back.”
In the current review, Fenton suggests that intense lobbying by manufacturers of the technology, combined with the politically volatile issue of breast cancer screening, resulted in fast-track approval by the government of Medicare coverage of the device.
He also argues that industry representatives were better able to market the device, which require a large capital investment of more than $100,000, after providers were assured their costs would be reimbursed by the government insurance program.
In an accompanying commentary in the same issue of the Archives, Karla Kerlikowske, professor of medicine, epidemiology and biostatistics at UC San Francisco, says health-care providers and others cannot presume that newer technologies are better than existing ones.
“Health-care providers should not adopt new technologies without first demanding scientific evidence beyond that required for FDA approval,” she writes, adding that such evidence should include not just clinical benefits, but also important associated harms and whether benefits outweigh those harms.
Researchers at the University of Minnesota and the University of Washington contributed to the study.
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