What are the guidelines for osteoporosis screening in post-menopausal women?

Osteoporosis Screening Guidelines for Postmenopausal Women

All postmenopausal women aged 65 years and older should undergo routine DXA screening of the hip and lumbar spine, regardless of risk factors. 1, 2

Age-Based Screening Algorithm

Women ≥65 Years

• Screen all women routinely with DXA at the femoral neck and lumbar spine, as this is the gold standard and best predictor of hip fracture risk 1, 2
• No additional risk factor assessment is required to justify screening in this age group 3, 2
• The USPSTF gives this a Grade B recommendation based on good evidence that screening and treatment reduce fracture risk 3

Women 60-64 Years

• Screen only if risk factors are present, as the benefits in this group are comparable to routine screening in older women when risk factors exist 1
• This represents a Grade B recommendation from the USPSTF 3

Women <60 Years (Postmenopausal)

• Do not routinely screen unless risk factors are present 1
• The USPSTF makes no recommendation for or against screening in this group (Grade C), reflecting insufficient evidence of benefit 3

Key Risk Factors That Trigger Earlier Screening

When evaluating postmenopausal women under 65 years, screen with DXA if any of the following are present:

• Low body weight (<70 kg) - this is the single best predictor of low bone mineral density 1
• Previous fragility fracture at any age 1
• Long-term glucocorticoid therapy 1
• Medical conditions causing bone loss: hyperparathyroidism, hypogonadism, chronic inflammatory diseases 1
• No current estrogen therapy use 1
• Family history of osteoporosis (weaker evidence as a sole trigger) 1

The International Society for Clinical Densitometry endorses DXA testing in postmenopausal women younger than 65 years only when clinical risk factors for low bone mass are present 4.

Screening Method Specifics

• DXA of the femoral neck is the best predictor of hip fracture and should be the primary measurement site 1, 5
• Lumbar spine should also be measured as part of comprehensive assessment 2
• Alternative methods exist (quantitative ultrasonography, radiographic absorptiometry) but DXA remains the validated standard 1

Rescreening Intervals

• Minimum 2 years between DXA scans is needed to reliably measure bone density changes 1, 2
• For normal bone density or mild osteopenia: repeat in 2-3 years 1
• For diagnosed osteoporosis or patients on treatment: repeat in 1-2 years to monitor treatment effectiveness 1
• Higher yield from repeated screening occurs in older women, those with lower baseline BMD, and those with other fracture risk factors 1, 2

Clinical Decision Support

• Use the FRAX tool to calculate 10-year fracture risk, which helps guide treatment decisions beyond just BMD values 1, 2
• The 10-year fracture risk in a 65-year-old white woman without additional risk factors is 9.3% 2

Important Caveats

• African-American women have higher average BMD than white women at the same age and are less likely to benefit from screening 3
• Diagnosis thresholds vary depending on measurement site, densitometer brand, and reference ranges used 1
• Some patients may qualify for treatment based on vertebral fractures detected through vertebral fracture assessment scans, even if BMD is above the osteoporosis threshold 1
• Bone density measurements have moderate to high sensitivity but low specificity for predicting fractures 5