What is the role of the FRAX (Fracture Risk Assessment) tool in assessing osteoporosis risk and guiding treatment decisions?

The Role of FRAX Tool in Assessing Osteoporosis Risk and Guiding Treatment Decisions

The FRAX (Fracture Risk Assessment) tool is a validated and essential clinical instrument for calculating 10-year fracture probability that should be used to guide treatment decisions in osteoporosis management, particularly for postmenopausal women and men over 50 years with risk factors for fracture. 1

What is FRAX?

• FRAX is a computer-based algorithm developed by the Sheffield WHO Collaborating Centre for Metabolic Bone Diseases, first released in 2008, intended for use in primary care settings 2
• It calculates the 10-year probability of a major osteoporotic fracture (hip, clinical spine, humerus, or wrist) and the 10-year probability of hip fracture specifically 2
• FRAX incorporates easily obtainable clinical risk factors including age, BMI, prior fragility fracture, parental history of hip fracture, current tobacco smoking, long-term use of oral glucocorticoids, rheumatoid arthritis, secondary osteoporosis, and excessive alcohol consumption 2
• Femoral neck bone mineral density (BMD) can be optionally included to enhance fracture risk prediction, though FRAX can be used with or without BMD data 2, 1

Clinical Applications of FRAX

Primary Indications

• FRAX helps identify patients who would benefit from pharmacologic treatment, particularly those with osteopenia (T-score between -1.0 and -2.5) whose fracture risk may not be captured by BMD alone 1, 3
• According to the National Osteoporosis Foundation guidelines, treatment is recommended for patients with FRAX 10-year risk scores of ≥3% for hip fracture or ≥20% for major osteoporotic fracture 1, 3
• FRAX addresses the limitation that BMD alone is not very sensitive - while people with low BMD are individually at high risk, the majority of fractures occur in the population with BMD above the T-score threshold of -2.5 2

Special Populations

• For adults ≥40 years initiating glucocorticoid therapy, FRAX with glucocorticoid dose adjustment should be used within 6 months of starting treatment 2, 1
• When using FRAX for patients on glucocorticoids >7.5 mg/day, the fracture risk should be increased by a relative 15% for major osteoporotic fracture and 20% for hip fracture risk 2
• FRAX is validated for use in untreated patients aged 40-90 years; it is not validated for use in patients <40 years of age 1, 3

Advantages of FRAX Over Other Assessment Methods

• FRAX provides improved fracture risk prediction compared to simplified tools, with studies showing significant improvement in risk categorization for those who remain fracture-free 4
• The tool incorporates country-specific versions calibrated using local fracture incidence and mortality data, making predictions more relevant to specific populations 2
• FRAX probability integrates both risk of fracture and risk of death, representing lifetime probability of fracture at older ages when life expectancy might be <10 years 2
• FRAX can be calculated with or without BMD and potentially supplemented with trabecular bone score (a measure of bone microarchitecture) 2

Limitations and Considerations

• FRAX has limitations regarding race-specific calculations, which may lead to differences in treatment recommendations among persons with otherwise identical risk profiles 2
• The tool uses binary exposure to glucocorticoids and alcohol use (yes/no vs. quantified dose exposure) rather than accounting for dose-dependent effects 2
• FRAX does not account for falls history or frailty, which are important risk factors for fracture 2
• The predictive accuracy of FRAX improves when BMD is included in the risk assessment calculation 2, 1
• FRAX should not be used to assess the reduction in fracture risk in individuals on treatment, though it may still have value for guiding the need for continued treatment or treatment withdrawal 5

Reassessment Intervals

• For adults ≥40 years on continued glucocorticoid treatment who are not on osteoporosis medication, FRAX reassessment should be completed every 1-3 years 1
• Earlier reassessment within this timeframe is recommended for patients on very high-dose glucocorticoids 1
• For patients with a history of osteoporotic fracture, reassessment should be performed more frequently 1

Integration with Clinical Practice

• FRAX should be used alongside clinical fracture risk assessment, which includes evaluation of falls, fractures, frailty, and other risk factors 1
• When available, including BMD measurements from DXA improves the accuracy of FRAX predictions 2, 1
• FRAX has been incorporated into DXA reporting software and electronic health record systems to facilitate clinical use 2, 3
• The use of fracture risk in deciding who to treat, when to treat, and what agent to use is a mechanism to target treatment equitably to those at increased risk of fracture 6

FRAX represents a significant advancement in osteoporosis management by enabling clinicians to move beyond BMD alone to assess fracture risk and make evidence-based treatment decisions that can reduce the substantial burden of osteoporosis-related fractures.