Are repeat bone density tests also covered as a screening test?

Repeat Bone Density Tests as Screening Tests

Yes, repeat bone density tests are covered as screening tests, but they should follow specific intervals based on baseline results and risk factors. 1

Recommended Intervals for Repeat Bone Density Screening

The U.S. Preventive Services Task Force (USPSTF) provides guidance on repeat bone density testing as a screening tool:

• Minimum interval: A minimum of 2 years between tests is needed to reliably measure changes in bone mineral density due to limitations in testing precision 1
• Individualized intervals: Longer intervals may be appropriate for identifying new cases of osteoporosis, with frequency determined by:
  • Age (older women need more frequent screening)
  • Baseline bone mineral density (lower BMD requires more frequent screening)
  • Presence of other risk factors for fracture 1

Higher Yield Groups for Repeat Screening

Repeat screening will provide greater clinical benefit in:

• Older women
• Those with lower bone mineral density at baseline
• Individuals with multiple risk factors for fracture 1

Special Considerations for Different Populations

For Women Under Age 65

• Women aged 60-64 with risk factors should receive screening comparable to routine screening in older women 1
• Key risk factors include:
  • Low body weight (weight < 70 kg) - strongest single predictor
  • No current use of estrogen therapy
  • Prior fractures 1

For Monitoring Treatment Response

• Patients diagnosed with osteoporosis are no longer in the screening context
• These patients may require additional testing for:
  • Diagnostic purposes
  • Monitoring response to treatment 1

Technical Aspects of Bone Density Testing

• Preferred measurement: Femoral neck bone density measured by dual-energy x-ray absorptiometry (DXA) is the best predictor of hip fracture 1
• Measurement variability: Results can vary significantly depending on:
  • Site and type of bone measurement test
  • Number of sites tested
  • Brand of densitometer used
  • Reference range applied 1

Common Pitfalls to Avoid

1. Testing too frequently: Testing more often than every 2 years typically cannot reliably detect true changes in bone density 1
2. Using T-scores for premenopausal women: BMD Z-scores (not T-scores) should be reported for all children, adolescents, and premenopausal women 1
3. Failing to adjust for growth factors in younger patients: For patients under 20 years, measurements should be adjusted for growth delay or maturational delay 1
4. Not considering risk factors when determining screening intervals: Higher risk individuals benefit from more frequent screening 1

By following these evidence-based guidelines for repeat bone density testing, clinicians can appropriately screen patients while avoiding unnecessary testing, ultimately improving fracture risk assessment and prevention.