Impact of FRAX-based osteoporosis intervention using real world data.

Objective: To estimate the implications and accuracy of the most common fracture prevention strategies: (1) fixed threshold by the National Osteoporosis Foundation (NOF), (2) age-dependent threshold by the National Osteoporosis Guideline Group (NOGG) and (3) osteoporotic bone mineral density (BMD).

Methods: A retrospective cohort of all 50-90years old female members in a nationally representative payer provider healthcare organization in Israel, with 10years of follow-up on incident events of major osteoporotic fractures. Since events are less frequent than non-events, balanced accuracy (the average between the accuracy obtained for patients with and without events) was used to measure performance.

Results: Overall among 141,320 women NOF and NOGG would recommend therapy for 17.3% and 2.8% respectively, with NOF exhibiting higher balanced accuracy: 74.1% vs. 54.2% for incident hip fractures detection and 60.0% vs. 51.6% for a composite outcome of major osteoporotic fractures. In patients with available BMD (n=16,578) the treatment intervention criteria of NOF, NOGG, osteoporotic femur neck or vertebral BMD were met by 30.5%, 9.3% and 24.6% of the population, with balanced accuracy of 70.1%, 56.5% and 62.3% respectively for hip fractures and 61.4%, 52.8%, 58.1% for major osteoporotic fractures. At the age of 75years or older the NOF hip fracture risk threshold (3%) was exceeded in most women regardless of risk factors other than age.

Conclusions: In this large population-based study, detection of patients at high risk of sustaining a major osteoporotic fracture within 10 years was more accurate with the NOF fixed threshold criteria as compared with the age-varying NOGG or BMD-only. However, special consideration and further studies are warranted in patients aged 75years or older with preserved bone density, which may benefit from non-medicinal interventions.