Calculator Guides
FRAX Score: Fracture Risk Assessment and Osteoporosis Management
FRAX calculates 10-year probability of major osteoporotic fracture (MOF) and hip fracture using 12 clinical risk factors with or without bone mineral density. A FRAX-based treat threshold of ≥20% MOF or ≥3% hip fracture is widely used in the US. FRAXplus (2024) addresses several limitations.
TL;DR: FRAX calculates 10-year probability of major osteoporotic fracture and hip fracture using 12 clinical risk factors with or without BMD. Treat threshold: ≥20% MOF or ≥3% hip fracture (US). FRAXplus (2024) addresses several limitations.
FRAX Input Variables
Age, sex, weight, height, prior fragility fracture, parental hip fracture, current smoking, glucocorticoids, rheumatoid arthritis, secondary osteoporosis, alcohol ≥3 units/day, femoral neck BMD T-score (optional).
Treatment Thresholds
| Outcome | Threshold |
|---|---|
| Major osteoporotic fracture | ≥20% → Treat |
| Hip fracture | ≥3% → Treat |
Evidence
Schini M et al. (2024) reviewed FRAX across 15 years — incorporated into 80+ national guidelines covering 79% of the world population.
Kanis JA et al. (2017) documented 63 country models and treatment efficacy correlation with baseline FRAX probability.
References
- Schini M, et al. J Endocrinol Invest. 2024;47(3):501–511. PMID: 37874461.
- Kanis JA, et al. J Clin Densitom. 2017;20(3):360–367. PMID: 28732576.
- McCloskey EV, et al. Curr Opin Rheumatol. 2016;28(4):433–441. PMID: 27163858.