People overestimate benefits of cancer, other prevention aids: study

For three of the four interventions, the event to be avoided was death. In the case of the bone drugs, it was hip fracture.

For breast cancer screening, only seven percent of the participants answered in the correct range of one to five lives being saved with screening, whereas 80 percent overestimated how many lives would be saved. Fully a third thought that 1,000 deaths would be averted.

The numbers were similar for bowel cancer screening, which is thought to save 5 to 10 lives for every 5,000 people tested.

Eighty-two percent of participants overestimated the number of fractures prevented by bone-strengthening medication, which i ins reality is about 50 for every 5,000 patients. And 69 percent of participants reported that 500 or move lives would be saved if 5,000 people took blood pressure medication, when the correct range should have been 50 to 100.

Hudson said that one of the problems that can arise when people overvalue a test is if recommendations for testing are scaled back because of insufficient benefits, people get upset.

In 2009, for instance, when guidelines were changed on regular mammograms from beginning at age 40 to beginning at age 50, a survey of women at the time found that most of them considered the new guidelines to be unsafe, at least in part because they feared that insurers

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