Managing osteoporosis with FRAX® in Australia: proposed new treatment thresholds from the 45&Up Study cohort.

Introduction: Many people at high risk of fractures are not following traditional guidelines and not being recommended for intervention. This study aimed to propose and evaluate a new set of intervention thresholds.

Methods: Participants were 213,375 men and women aged ≥50 years living in New South Wales, Australia. Fracture Risk Assessment Paper Charts (Australia) was used to estimate the 10-year fracture risk. The standardized rates (to Australia population distribution 2007) for intervention were calculated for different thresholds: our proposed new thresholds (i.e. 10-year probability of hip fracture: ≥3%, 5% or 7% for 50-69, 70-79 and ≥80 years respectively), thresholds by the National Osteoporosis Guideline Group (NOGG) approach, UK thresholds and US thresholds.

Results: The NOGG, UK and US thresholds did not work well in the Australian population. For example, the NOGG and UK thresholds respectively qualified only 1 in 12 (8.1%) and 1 in 9 (11.3%) Australian men aged ≥70 years and the US thresholds qualified about 9 in 10 (90.6%) Australian women aged ≥ 70 years. For men or women aged ≥70 years, our proposed new thresholds gave more realistic treatment rates of 21.6% for men and 70.5% for women. Compared to the current Australian guidelines (i.e. T-score ≤ -2.5 and age ≥ 70 years or a fragility fracture), our thresholds identified an additional 4.9% of men and 18.2% of women aged ≥ 70 years for treatment.

Conclusion: The proposed new thresholds could identify currently under-recognised high-risk individuals for treatment. It should be considered as a recommendation for osteoporosis management in Australia.