Four-year repeat of bone mineral density screening in seniors offers limited value

Repeating bone mineral density (BMD) tests after four years provides little clinical benefit when assessing bone fracture risk in seniors age 75 and older, according to a recent study led by researchers at the Harvard Medical School-affiliated Institute for Aging Research at Hebrew SeniorLife. The study appears in the Sept. 25 online issue of JAMA.

BMD testing is an important tool in osteoporosis risk assessment and management, although there are no established guidelines for the appropriate time interval between tests. Medicare pays for BMD screening every two years without restricting the number of repeat tests and regardless of baseline test results.

"Given the drive to control health care costs while improving quality of care, we wanted to determine whether repeating a BMD screening test is useful," explained Sarah Berry, M.D., M.P.H., the study's lead author.

Dr. Berry and her colleagues studied 310 men and 492 women whose BMD was assessed twice between 1987 and 1999 as part of the Framingham Osteoporosis Study. This ancillary study of the Framingham Heart Study was led by Dr. Douglas P. Kiel, one of Dr. Berry's co-authors.

"Our research, which was made possible through the routine clinical examinations performed as part of the Framingham Heart Study, tells us that the initial BMD test does a very good job of identifying people at risk for fracture," Berry said. "The current clinical practice of repeating the test every two years may not be necessary in adults over age 75 who aren't being treated for osteoporosis."

BMD is included in the Fracture Risk Assessment Tool (FRAX), a widely used calculator that estimates the 10-year risk of major fracture related to osteoporosis. The tool also considers clinical characteristics, such as age and fracture history, which are fracture risk factors. "Instead of repeating the BMD test, we recommend that providers update the patient's clinical characteristics in the tool at the time of the visit to reassess fracture risk," Dr. Berry said.

Although 10 million people in the U.S. have osteoporosis and 18 million more are at risk for the disease, only five percent of Medicare beneficiaries age 75 and older have a BMD screening in a given year. The low screening rate reflects a lack of public understanding about osteoporosis, noted Dr. Berry.

"It's a silent disease that people don't recognize until they have a fracture, and at that point the damage is done. Based on our research, I hope that resources will be used more judiciously so that more elders get a baseline BMD screening test and fewer get a repeat test in a short time period."