Validation of the FRAX Predictive Model for Major Osteoporotic Fracture in a Historical Cohort of Spanish Women

Abstract FRAX is a fracture risk assessment tool to estimate the 10-yr probability of a major osteoporotic fracture or a hip fracture. The aim of the study was to assess the predictive ability of FRAX for major osteoporotic fracture in a cohort of Spanish women. The study was based on a retrospective cohort of women aged 40–90yr. Patients were followed from their first bone densitometry to the first major osteoporotic fracture event (forearm, proximal humerus, clinical spine, or hip fracture) or for 10yr whichever comes first. A total of 1231 women were included. Bone mineral density data and self-reported data on risk factors for fracture were obtained. The predictive ability of FRAX was assessed by analyzing calibration and discrimination, with the calculation of observed-to-expected (O/E) fracture ratios and the receiver operating characteristic (ROC) curve, respectively. A total of 222 women (18.1%) reported at least 1 fracture after the first assessment. The incidence of fracture was 14 (95% confidence interval [CI]: 10–17), 19 (95% CI: 15–23), 28 (95% CI: 21–36), and 67 (95% CI: 8–125) cases per 1000 woman-years in women aged p FRAX underestimated the risk of major osteoporotic fracture in this cohort of Spanish women, particularly in those with a low risk of fracture according to the clinical factors used in the FRAX tool. Our findings highlight the need for validation studies of FRAX in Spain.