The Fracture Risk Assessment Tool (FRAX) Calculator is a widely used clinical tool designed to estimate an individual’s 10-year probability of experiencing a major osteoporotic fracture, such as a hip, spine, forearm, or shoulder fracture. Developed by the World Health Organization (WHO), the FRAX tool integrates multiple risk factors to provide a comprehensive assessment of fracture risk, helping healthcare providers make informed decisions about osteoporosis management and fracture prevention strategies.
The FRAX Calculator incorporates various clinical risk factors along with bone mineral density (BMD) measurements, if available, to estimate fracture risk. The key risk factors used in the FRAX calculation include:
- Age and Sex: Older age and female sex are significant risk factors for fractures.
- Body Mass Index (BMI): Lower BMI is associated with an increased risk of fractures.
- Previous Fracture: A history of previous fractures increases the risk of future fractures.
- Parental History of Hip Fracture: A family history of hip fractures suggests a genetic predisposition to bone fragility.
- Glucocorticoid Use: Long-term use of glucocorticoid medications (e.g., prednisone) is linked to decreased bone density and increased fracture risk.
- Rheumatoid Arthritis: This condition is associated with an increased risk of fractures due to inflammation and decreased bone quality.
- Smoking: Current smoking contributes to reduced bone density and higher fracture risk.
- Alcohol Intake: High alcohol consumption (three or more units per day) negatively affects bone health.
- Secondary Osteoporosis: Conditions such as type 1 diabetes, osteogenesis imperfecta, untreated hyperthyroidism, hypogonadism, premature menopause, chronic malnutrition, or malabsorption can contribute to increased fracture risk.
- Bone Mineral Density (BMD) at the Femoral Neck: If available, BMD data significantly enhance the accuracy of the FRAX risk prediction.
To use the FRAX Calculator, the healthcare provider enters the relevant data for the patient, including the presence of risk factors and BMD if available. The calculator then estimates the 10-year probability of a major osteoporotic fracture and a hip fracture, expressed as a percentage.
Interpreting the FRAX results involves comparing the calculated risk with established thresholds to guide treatment decisions. For example, in many guidelines, a 10-year probability of a major osteoporotic fracture above a certain percentage (often 20%) or a hip fracture above a specific threshold (often 3%) may indicate the need for pharmacological intervention, such as bisphosphonates, to reduce fracture risk. Lower risk scores might lead to recommendations for lifestyle modifications, dietary supplementation with calcium and vitamin D, and regular weight-bearing exercise to maintain bone health.
The FRAX Calculator is particularly useful in identifying individuals who may not meet traditional criteria for osteoporosis based on BMD alone but still have a significant fracture risk due to other factors. This allows for a more personalized and targeted approach to fracture prevention, optimizing patient care.
