Little Benefit Seen in Repeat Bone-Density Testing
TUESDAY, Sept. 24 -- For many seniors, it may not be worthwhile to undergo frequent imaging tests to see if they're at risk for broken bones, a new study suggests.
Repeating a bone-mineral-density test four years after the initial one did not provide substantially more information to predict fracture risk among older men and women who did not yet have osteoporosis, the study found.
"We found that the initial bone-density test did a good job of identifying individuals at risk for a fracture," said Dr. Sarah D. Berry, a research scientist at the Institute for Aging Research at Hebrew Senior Life and an assistant professor of medicine at Harvard Medical School in Boston.
The bone-mineral-density DEXA test often is repeated every two years, Berry said, as Medicare part B will reimburse for it every two years, and more often if medically necessary. DEXA stands for dual energy X-ray absorptiometry. People with lower bone density are at greater risk for breaking a bone.
The study, which included more than 800 men and women with an average age of 75, is published in the Sept. 25 issue of the Journal of the American Medical Association.
Berry's study was conducted to determine if testing at a four-year interval was excessive and could be skipped without harm, thereby saving health care dollars. Currently, about 22 percent of screened Medicare patients get a repeat test, on average about 2.2 years apart, according to background information included in the study.
Berry's team followed the participants for about 10 years, on average. They found that during that time, 113 people had one or more major fractures. When they looked to see if the results of the second test predicted fractures, they found that it provided little additional information.
"Of those who went on to experience a hip fracture, repeating a bone-density test improved our ability to classify a person at higher risk by about 4 percent," Berry said.
She said the message is not to ignore fracture risk, and that the study only speaks about the four-year interval, not beyond. "What our study suggests is that a doctor should routinely reassess risk," she said, but could probably do that without a repeat bone-density test very two years.
Instead, the doctor could look at the initial test and update information by considering the person's current age and weight and using the online FRAX tool, a standard fracture-assessment tool developed by the World Health Organization that evaluates the 10-year risk of fracture.
Another expert, however, had some qualms. "I think studies like this tend to be overinterpreted in terms of saving money," said Dr. Robert Recker, president of the National Osteoporosis Foundation and director of the Osteoporosis Research Center at Creighton University, in Omaha, Neb.
"Each patient is a different situation," he said, adding that doctors need to decide on a case-by-case basis about follow-up testing for risk prediction.
Recker also said the number of people in the study is relatively small, and that the researchers also excluded those with a hip fracture prior to the second test, because they would have been prescribed medication to increase bone density. "The high-risk [participants] are already removed from the sample," he said.
The National Osteoporosis Foundation recommends bone-density testing in women aged 65 and older and men aged 70 and older, or earlier if there are risk factors such as a fracture history.
To learn more about the bone-density test, visit the National Osteoporosis Foundation.
Posted: September 2013