A new study supports getting mammograms every other year instead of annually.

It finds that more than 60 percent of women who get tested each year for a decade will be called back at least once for extra tests that turn out not to show breast cancer.

Screening every other year, as a government task force recommends, drops this false alarm rate to 42 percent without a big risk of cancer being found at a late stage, the study suggests. Having your previous mammogram available for comparison to the new one cuts the chance of a false alarm in half.

The study appears in the Annals of Internal Medicine. It does not get into the debate over whether mammograms should start at age 40 or 50.