What does FRAX estimate?

• A. Vitamin D level
• B. Serum calcium level
• C. 10-year probability of fracture
• D. Current bone density

Answer: (C)

FRAX is a fracture risk calculator that estimates the likelihood of a fracture over the next decade. It uses a combination of clinical risk factors (age, sex, prior fracture, family history of hip fracture, smoking, glucocorticoid use, rheumatoid arthritis, secondary osteoporosis, alcohol, height/weight) and can include femoral neck bone mineral density to refine the estimate. The output provides two percentages: the 10-year probability of any major osteoporotic fracture (spine, hip, forearm, shoulder) and the 10-year probability of hip fracture. It does not measure current bone density by itself, nor does it report vitamin D or calcium levels; BMD input, if used, helps tailor the risk but FRAX’s main function is projecting future fracture risk.