ATLANTA — New research could mean millions of older women can skip frequent screening tests for osteoporosis. If an initial bone scan shows no big problems, many can safely wait 15 years to have another one, the study suggests.

Government advisers and leading doctor groups urge osteoporosis screening but no one has known how often that should happen. The findings offer the best information to date on that question, experts said.

“This is landmark, in the sense that it could allow us to move on to more precise guidelines,” said Dr. Heidi Nelson, a researcher at the Oregon Health & Science University, who is an expert on the topic.

At issue are bone mineral density tests, which usually are done through X-rays and cost around $250. It takes about 10 minutes and involves less radiation than what's emitted during a chest X-ray. Medicare pays for testing every two years.

The new study feeds concerns that the tests are done too often, at least for some women.

“It's an expenditure of time, it's exposure to radiation and it's cost. And there's no reason to expose yourself to any risks if there's going to be no benefit,” said Dr. Virginia Moyer, who heads the U.S. Preventive Services Task Force, a government panel that issues testing guidelines.

The test measures how thick bones are in certain spots, usually focusing on the hip and lower spine. Doctors use it to gain early warning of osteoporosis, a bone-thinning disease that can be staved off with better diet and exercise and treated with bone-building drugs. Nearly half of all women older than 50 will break a bone because of osteoporosis, according to the National Osteoporosis Foundation.

The government task force recommends that all women over 65 get a scan. The panel also recommends testing for younger postmenopausal women who seem at higher risk for fractures. But the task force has not said how often follow-up tests should be done, just that a couple years between tests are needed.

There are no immediate plans to update the task force's advice for osteoporosis screenings but the new study will be an important consideration when the panel acts again, Moyer said.

ON THE NET
New England Journal: nejm.org

Osteoporosis information: bones.nih.gov