Serial Bone Density Measurement and Incident Fracture Risk Discrimination in Postmenopausal Women.

Area of Science:

• Gerontology
• Osteoporosis Research
• Bone Health

Background:

• Repeated bone mineral density (BMD) testing is resource-intensive.
• Determining the value of serial BMD measurements is crucial for patient counseling and efficient resource allocation.
• Understanding if BMD changes improve fracture risk discrimination beyond baseline is key.

Purpose of the Study:

• To evaluate if a second BMD measurement, taken around 3 years post-initial assessment, enhances fracture risk prediction.
• To compare the predictive ability of baseline BMD alone versus baseline BMD plus BMD change for future fractures.

Main Methods:

• Prospective observational cohort study (Women's Health Initiative) with 7419 participants.
• Assessed incident major osteoporotic fractures and hip fractures over a mean follow-up of 9.0 years post-second BMD measurement.
• Calculated area under the receiver operating characteristic curve (AU-ROC) to compare discrimination of baseline BMD, BMD change, and their combination.

Main Results:

• Baseline total hip BMD showed an AU-ROC of 0.71 for hip fracture discrimination.
• The combination of baseline and change in total hip BMD yielded an AU-ROC of 0.73, a minimal improvement.
• For major osteoporotic fracture, baseline BMD and the combination showed similar discrimination (AU-ROC 0.61).

Conclusions:

• A second BMD measurement approximately 3 years after the initial one does not significantly improve fracture risk discrimination.
• Routine repeat BMD testing beyond baseline measurement is not recommended for postmenopausal women.
• Baseline BMD alone appears adequate for assessing fracture risk, optimizing clinical decisions and resource use.