Targeted vertebral fracture assessment for optimizing fracture prevention in Canada

Vertebral fracture assessment (VFA) provides incremental information in identifying women and men aged 70 years and older qualifying for anti-osteoporosis treatment compared with FRAX^® major osteoporotic fracture (MOF) probability computed with bone mineral density (BMD).

This analysis was performed to inform appropriate use of VFA testing as part of Osteoporosis Canada's Guidelines Update, assuming vertebral fracture is an indication for pharmacotherapy in women and men.

Women and men aged 70 years and older without previous high-risk fracture (i.e., hip, spine, or multiple fractures) were identified in a BMD registry for the province of Manitoba, Canada. MOF probability with BMD was computed using the Canadian FRAX^® tool. VFA was performed in those with a minimum BMD T-score of -1.5 or lower.

The study population consisted of 7289 women (mean age 76.7 ± 5.6 years) and 1323 men (77.9 ± 5.8 years). More women than men qualified for VFA testing (48.7% vs 25.4%, respectively, p < 0.001). Among those undergoing VFA, a vertebral fracture was more commonly detected among men than women (22.9% vs 13.3%, p < 0.001), and vertebral fracture prevalence increased with lower BMD T-score (both p trend <0.001). The number needed to screen with VFA to detect a vertebral fracture was 8 for women and 4 for men. MOF probability was substantially lower in men than in women, and fewer men than women (3.3% vs 20.2%, p < 0.001) met a treatment threshold of MOF 20% or greater. In those with MOF probability <20%, VFA identified an incremental 5.4% of men and 3.4% of women for treatment based upon vertebral fracture.

The number needed to screen to identify a previously unappreciated vertebral fracture is low and further improves with lower BMD T-score. VFA identified more men as qualifying for treatment than MOF probability. In women, treatment qualification was predominantly from MOF probability.