Validation of the Taiwan FRAX® calculator for the prediction of fracture risk.

ABSTRACT

The Taiwan FRAX® calculator was validated to predict incident fractures preliminarily. Cutoffs of FRAX probability for predicting major osteoporotic fracture and hip fracture were proposed as 9.5% and 4% in Taiwanese individuals. PURPOSE: FRAX® is an algorithm used to calculate fracture probabilities based on clinical risk factors (CRFs) and bone mineral density (BMD). The country-specific Taiwan FRAX calculator has not been validated since its establishment in 2010. The aim of the present study is to evaluate the predictive performance of the Taiwan FRAX calculator using longitudinal fracture data. METHODS: A total of 1975 subjects, aged ≧ 40 years old, from Yunlin and Tianliao cohorts in Taiwan during the period 2009-2010, were identified and completely connected with the 2008-2016 National Health Insurance Research Database. RESULTS: During the average 6.8 ± 1.1 years of follow-up, 160 incident major osteoporotic fractures (MOFs) were identified. The predictive ability assessing based on the observed to expected fractures (O/E) ratio calculated with the FRAX probability adjusted for 6.8 years were 1.19 (95%CI 1.02-1.39) for MOF, and 1.07 (95%CI 0.82-1.39) for hip fractures. In the discriminative statistics, the AUC for prediction of major osteoporotic fractures using FRAX was 0.75 without and 0.77 with BMD (AUC for hip fracture was 0.75 without and 0.77 with BMD). The optimal cutoff value was 9.5% of the FRAX score with BMD for all major osteoporotic fractures, with good sensitivity (76.9%) and specificity (65.3%). For hip fractures, the optimal cutoff point for the FRAX probability with BMD was 4.0%, and the sensitivity and specificity were 74.4% and 68.3%, respectively. CONCLUSION: The Taiwan FRAX® calculator was validated to predict incident fractures preliminarily. Cutoffs are proposed for predicting fracture risk in Taiwanese individuals.