The current practice of testing bone mineral density every 2 years in older adults may be too frequent, suggests a JAMA study.
Roughly 800 adults (mean age, 75) underwent two femoral neck BMD tests an average of 3.7 years apart as part of the Framingham Osteoporosis Study. After 10 years of follow-up, the addition of BMD change to a model predicting fracture risk did no better than use of baseline BMD alone. With a second BMD test, the percentage of patients with a hip fracture reclassified as high risk increased only 3.9%, while those with a major osteoporotic fracture who were upgraded to high risk increased 9.7%.
The authors conclude: "The current clinical practice of repeating a BMD test every 2 years to improve fracture risk stratification may not be necessary in all adults 75 years or older untreated for osteoporosis. Further study is needed to determine an appropriate rescreening interval and to identify individuals who might benefit from more frequent rescreening intervals."
In a comment about this article the JAMA editor states that "This analysis challenges the practice of repeating bone-mineral density tests routinely every few years. Very few older women with normal BMD developed osteoporosis within 15 years after a normal test result. For women whose baseline BMDs fell within the lower portion of the osteopenic range, screening intervals required to avoid missing the development of osteoporosis were progressively shorter. Future updates of screening guidelines should incorporate these findings. However, keep in mind that factors other than BMD affect fracture risk, and that this study did not address who might benefit from treatment.