Repeat BMD screens unlikely to change osteoporosis management

Older patients who aren't being treated for osteoporosis may not benefit from frequent repetition of bone mineral density (BMD) testing, a new study found.

The cohort study included 310 men and 492 women from the Framingham Osteoporosis Study who underwent femoral neck BMD scans twice between 1987 and 1999 and were followed for hip or major osteoporotic fractures for a median of 9.6 years. The mean age of the patients was 74.8 years. Results were published in the Sept. 25 Journal of the American Medical Association.

During follow-up, 76 participants had a hip fracture and 113 had a major osteoporotic fracture. The researchers found that decrease in BMD over an average of 3.7 years was independently associated with both types of fracture. At 10 years' follow-up, a BMD decrease 1 standard deviation greater than the average was associated with 3.9 excess hip fractures per 100 persons. However, adding BMD change to a risk prediction model based on baseline BMD did not meaningfully improve prediction of fractures, the study found. Only an insignificant percentage of patients were reclassified to a higher-risk group.

The authors concluded that repeating a BMD test after 4 years would rarely change management of osteoporosis, especially because the study participants with the greatest change in BMD were already high risk based on their baseline measurement. The results raise questions about the benefits of the current practice in the U.S. of repeating BMD every 2 years even in patients not being treated for osteoporosis, the authors said.

The authors cautioned that their results may not apply to patients different from those in the study, which excluded some older patients and was conducted in the pre-bisphosphonate era. Further research is needed to determine which patients might change fracture-risk category within a few years and therefore benefit from repeat BMD, they said. Inclusion of family history of fracture could be helpful, the authors suggested. Other limitations of the study included use of 2 different machines for measuring BMD and a mostly white population.