The two absolute fracture risk calculators recommended in Australian osteoporosis guidelines give markedly different results for the same patients, a study shows.

Pitting the two tools against each other, researchers have shown GPs using the Garvan Fracture Risk Calculator might offer therapy to significantly more patients than those using FRAX (Fracture Risk Assessment Tool).

For example, a 60-year-old woman with a T-score of –3 would be recommended for treatment under the Garvan calculator, giving a 5% 10-year risk of hip fracture but not under FRAX, which would find a risk of 2%.

Under GP guidelines endorsed by the RACGP and Healthy Bones Australia (formerly Osteoporosis Australia), the threshold for preventive treatment based on fracture risk prediction is an absolute 10-year risk of hip fracture greater than 3% or a risk of any fracture of greater than 20%.