DEXA Screening Guidelines for Osteoporosis
All women aged ≥65 years and men aged ≥70 years should undergo DEXA screening, while postmenopausal women and men ≥50 years with specific risk factors require earlier screening. 1, 2
Universal Screening Recommendations
Women
- Age ≥65 years: Universal DEXA screening recommended regardless of risk factors 1, 2
- Age 50-64 years (postmenopausal): Use a 2-step approach:
- First assess fracture risk using clinical risk assessment tools (e.g., FRAX)
- If elevated risk identified, proceed to DEXA 1
Men
- Age ≥70 years: Universal DEXA screening recommended 2
- Age 50-69 years: Screen only if risk factors present 2
Risk-Based Screening (Age <65 Women, Age <70 Men)
DEXA is indicated for postmenopausal women and men ≥50 years with any of these risk factors 2:
Major Risk Factors
- Prior fragility fracture (any low-trauma fracture in adulthood)
- Chronic glucocorticoid use (≥5 mg prednisone equivalent daily for ≥3 months)
- Significant height loss:
- Historical: >4 cm (>1.5 inches) from peak height
- Prospective: ≥0.8 inch from last documented height
- Medical conditions causing bone loss:
- Hyperparathyroidism
- Rheumatoid arthritis
- Chronic kidney disease
- Malabsorption syndromes
- Hypogonadism
Additional Indications
- Prostate cancer on androgen deprivation therapy 2
- Spinal cord injury (requires specialized sites: total hip, proximal tibia, distal femur) 2
- Transgender persons: Based on hormone therapy compliance, gonadal removal, and additional risk factors 2
Measurement Sites
Standard DEXA should assess 2:
- Lumbar spine (L1-L4)
- Total hip
- Femoral neck
- One-third radius (if indicated, particularly in hyperparathyroidism)
Diagnosis of osteoporosis: T-score ≤-2.5 at any of these sites 2
Screening Intervals
Evidence on optimal screening intervals remains limited 1. Practical approach 2:
- Initial follow-up: 1-2 years after starting therapy
- Subsequent monitoring: Every 1-5 years depending on:
- Baseline fracture risk
- Treatment status
- Clinical stability
- Prior rate of bone loss
Vertebral Fracture Assessment (VFA)
Consider VFA or spine radiography when T-score <-1.0 plus any of 2:
- Women ≥70 years or men ≥80 years
- Historical height loss >4 cm
- Self-reported undocumented vertebral fracture
- Chronic glucocorticoid therapy
- Acute back pain with osteoporosis risk factors
Important Clinical Caveats
Artifacts That Invalidate Results
Lumbar spine should not be used if 2:
- Severe degenerative changes or facet sclerosis
- Compression fractures
- Abdominal aortic calcification overlying spine
- Prior spinal fusion or hardware
Hip should not be used if 2:
- Hip prosthesis or hardware present
- Advanced osteoarthritis with cortical thickening
- Severe hip dysplasia
Two-Step Approach for Younger Women
For postmenopausal women <65 years, the USPSTF recommends 1:
- First: Calculate fracture risk using validated tools (FRAX, Garvan, QFracture)
- Second: Order DEXA only if fracture risk is elevated
Note: The 9.3% 10-year major osteoporotic fracture risk threshold has low sensitivity (37%) for detecting osteoporosis in women ages 50-64 3. Consider lowering the threshold to 5.5% to increase sensitivity to 80%, though this reduces specificity 3.
Key Differences from Other Guidelines
- Canadian Task Force (2023): Recommends against screening men ≥40 and women <65 years, uses FRAX first, then DEXA only if considering pharmacotherapy 1
- AAFP: Specifically recommends against screening women <65 and men <70 without risk factors 1
- ACOG (2021): Aligns with USPSTF for age ≥65, selective screening <65 with formal risk assessment 1
Populations Requiring Specialized Consideration
Younger adults (<50 years, premenopausal women): DEXA indicated only with 2:
- Prior fragility fracture
- Diseases causing secondary osteoporosis
- Medications causing bone loss (glucocorticoids, aromatase inhibitors)
Use Z-scores (not T-scores) for interpretation in these populations 2.