We compared the utility of the current Romanian guidelines that recommend treatment in women with a T-score ≤-2.5 SD with a FRAX-based intervention threshold equivalent to women with a prior fragility fracture. Whereas the FRAX-based intervention threshold identified women at high fracture probability, the T-score threshold was less sensitive and decreased markedly with age.
Purpose: FRAX algorithm has been calibrated for Romania, but guidance is needed on how to apply fracture probabilities to clinical practice.
Methods: The age-specific 10-year probabilities of a major osteoporotic fracture were calculated at two potential intervention thresholds. The first comprised the age-specific fracture probabilities associated with a femoral neck T-score of -2.5 SD, in line with Romanian guidelines. The second approach determined age-specific fracture probabilities that were equivalent to a woman with a prior fragility fracture, without bone mineral density (BMD). The parsimonious use of BMD was additionally explored by the computation of upper and lower assessment thresholds for BMD testing.
Results: When a BMD T-score ≤-2.5 SD was used as an intervention threshold, FRAX probabilities in women aged 50 years were twofold higher than in women of the same age with an average BMD. The increase in risk associated with the BMD threshold decreased progressively with age such that, at the age of 80 years or more, a T-score of -2.5 SD was protective. The 10-year probability of a major osteoporotic fracture by age, equivalent to women with a previous fracture, rose from 5.3% at the age of 50 years to 13% at the age of 80 years and identified women at increased risk at all ages.
Conclusion: Intervention thresholds based on BMD alone do not effectively target women at high fracture risk, particularly in the elderly. In contrast, intervention thresholds based on fracture probabilities equivalent to a "fracture threshold" targets women at high fracture risk irrespective of age.