Fracture probability assessed without bone mineral density (BMD) could potentially be sufficient for clinical decision making in many individuals categorized as low or high fracture risk. For individuals falling in a moderate risk range, there is incremental value in using BMD in the probability calculation as this appropriately reclassifies risk in over one third of the individuals.
Introduction: A new fracture risk assessment tool from the World Health Organization (FRAX) estimates 10-year major osteoporotic and hip fracture probabilities from multiple clinical risk factors with or without hip BMD. The objective of this study is to determine whether fracture probability derived without BMD can be used to identify individuals who would be designated for treatment.
Methods: A historical cohort of 36,730 women and 2,873 men aged 50 years and older drawn from the Manitoba Bone Density Program database, which contains clinical BMD results for the Province of Manitoba, Canada, was included in the study.
Results: When 10-year probability for major osteoporotic fracture estimated without knowledge of BMD was high (≥ 20%), the vast majority (92.8%) qualified for intervention under the National Osteoporosis Foundation (NOF) guidelines, whereas among those at low risk (<10%), the vast majority (80.5%) did not satisfy any NOF intervention criteria. The benefit of including BMD in the risk assessment was greatest among those initially at moderate risk (10-19%) when fracture probability was derived without BMD, but this represented only 29.4% of the cohort (9.3% of those aged < 65 years and 48.7% of those ≥ 65 years).
Conclusions: Fracture probability derived without BMD is able to risk stratify women in terms of future fracture risk and could potentially be sufficient for clinical decision making in many of those designated at low or high fracture risk.