The role of bone mineral density in therapeutic decision-making using the Fracture Risk Assessment Tool (FRAX): a sub-study of the Taiwan OsteoPorosis Survey (TOPS)

Fracture Risk Assessment Tool (FRAX)-based intervention threshold (IT) is widely applied for treatment decision-making; however, an IT based on FRAX without the measurement of bone mass density (BMD) has not been validated. The study demonstrated that estimates of fracture risk by FRAX without BMD were higher than those by FRAX with BMD in women with old age. Introduction BMD is an integral component for bone strength assessment, but age-specific impacts of BMD on fracture risk assessment and therapeutic decision-making remained unclear. We aimed to investigate whether using BMD measurement changed the interpretation of the FRAX-based fracture probability assessment and treatment decision. Methodology The database was provided by the Taiwanese Osteoporosis Association (TOA) which conducted a nationwide survey of BMD. We calculated the 10-year major and hip fracture probabilities using the FRAX for each participant, either with (FRAX + BMD) or without BMD (FRAX - BMD). Age-specific individual intervention thresholds (IITs) were established using the FRAX-based fracture risk, equivalent to a woman with a prior fracture. Participants whose FRAX scores of major fracture were greater than or equal to their IITs were deemed suitable for therapeutic intervention. Results A total of 14,007 postmenopausal women were enrolled. Compared with FRAX + BMD, FRAX - BMD predicted lower FRAX scores in major and hip fractures in subjects aged 40-60 years; however, FRAX - BMD estimated higher risks for those aged 61-90 years. The therapeutic decision using FRAX - BMD was concordant to that using FRAX + BMD in 90.5% of the subjects, especially in the younger age group (40-70 years). FRAX - BMD identified more treatment candidates (7.7-16.4%) among those aged 71-90 years. Conclusions The FRAX scores are influenced by age, irrespective of the consideration of BMD. FRAX - BMD is able to identify more subjects for therapeutic intervention in the elderly population. We should reconsider the role of BMD at different ages for therapeutic decision-making.