Time to Clinically Relevant Fracture Risk Scores in Postmenopausal Women

Background Clinical practice guidelines recommend use of fracture risk scores for screening and pharmacologic treatment decisions. The timing of occurrence of treatment-level (according to 2014 National Osteoporosis Foundation guidelines) or screening-level (according to 2011 US Preventive Services Task Force guidelines) fracture risk scores has not been estimated in postmenopausal women. Methods We conducted a retrospective competing risk analysis of new occurrence of treatment-level and screening-level fracture risk scores in postmenopausal women aged 50 years and older, prior to receipt of pharmacologic treatment and prior to first hip or clinical vertebral fracture. Results In 54,280 postmenopausal women aged 50 to 64 years without a bone mineral density test, the time for 10% to develop a treatment-level FRAX score could not be estimated accurately because of rare incidence of treatment-level scores. In 6096 women who had FRAX scores calculated with bone mineral density, the estimated unadjusted time to treatment-level FRAX ranged from 7.6 years (95% confidence interval [CI], 6.6-8.7) for those aged 65 to 69, to 5.1 years (95% CI, 3.5-7.5) for those aged 75 to 79 at baseline. Of 17,967 women aged 50 to 64 with a screening-level FRAX at baseline, 100 (0.6%) experienced a hip or clinical vertebral fracture by age 65 years. Conclusions Postmenopausal women with sub-threshold fracture risk scores at baseline were unlikely to develop a treatment-level FRAX score between ages 50 and 64 years. After age 65, the increased incidence of treatment-level fracture risk scores, osteoporosis, and major osteoporotic fracture supports more frequent consideration of FRAX and bone mineral density testing.