Selection of women aged 50-64 yr for bone density measurement

The fracture risk assessment tool from the World Health Organization (FRAX(®)) estimates 10-yr major osteoporotic and hip fracture probabilities from multiple clinical risk factors and optionally femoral neck bone mineral density (BMD). FRAX without BMD has been proposed as a method to select postmenopausal women younger than 65yr for BMD measurement, but the efficiency of this strategy and its concordance with National Osteoporosis Foundation (NOF) treatment guidelines is unknown. The osteoporosis self-assessment test (OST) is another simple screening tool based on age and weight alone. A historical cohort of 18,315 women aged 50-64yr, drawn from the Manitoba Bone Density Program database, which contains clinical BMD results for the Province of Manitoba, Canada, was used to determine the performance of these screening tools in selecting postmenopausal women younger than 65yr for BMD testing. FRAX was closely aligned with indicators of high fracture risk (area under the receiver operating characteristic curve [AUROC]: 0.89), whereas OST was better for detecting women with osteoporotic BMD (AUROC: 0.72). The combination of major fracture probability 10% or higher from FRAX without BMD or OST less than 1 identified 42% of women for BMD testing, capturing 72% of women meeting any NOF treatment criteria (90% of women with NOF criteria for high risk from FRAX or prior fracture). The negative predictive value to exclude qualification for treatment under the NOF criteria was 90%. These data may help to inform an evidence-based approach for targeting BMD testing in postmenopausal women younger than 65yr under the NOF treatment guidelines.