The Discriminative Ability of FRAX and Possible FRAX-based Intervention Thresholds for Beijing-dwelling People

Background The overall diagnosis and treatment rate of osteoporotic fractures is low in our county, and there is an urgent need to find reliable prediction tools. FRAX is a predictive tool recommended by Guidelines for the Diagnosis and Treatment of Primary Osteoporosis, but its predictive value and intervention threshold in the Chinese population need to be further verified. Objective To evaluate the predictive value of FRAX on fracture risk in Beijing residents and explore the intervention threshold. Methods One thousand and eighteen participants were randomly recruited from four community health service centers in Beijing during the period between 2011 and 2012. Based on the FRAX tool, the probability of major osteoporotic fracture (MOF) and hip fracture (HF) in the next 10 years were calculated for each participant. Osteoporotic fractures that occurred during the 10-year research period were self-reported, collected from 2021 to 2022. Taking the actual occurrence of fractures as the gold standard, the receiver operating characteristic (ROC) curve of FRAX for predicting fractures was drawn; the area under the curve (AUC) was analyzed for the predictive value of FRAX on fracture and the intervention threshold was explored. Results Four hundred and sixty-nine subjects were followed up successfully. The median probability of MOF and HF calculated by FRAX were 2.6% (2.2%, 3.7%) and 0.5% (0.3%, 0.9%), respectively. A total of 49 (10.45%) new MOF were occurred during the 10 years, of which 5 (1.07%) were HF. ROC analysis showed the AUCs of FRAX and femoral neck bone mineral density were 0.683 and 0.662, respectively. The cut-off value at which Yoden's index is maximum was 2.95% with a sensitivity of 59.2% and a specificity of 67.6%. Conclusion The FRAX tool has certain predictive power for future fractures, whereas there is still room for improvement. To predict major osteoporotic fractures, the probability of FRAX-MOF is 2.95%, which is the maximum cutoff value of Yoden's Index. It can be considered as a reference for formulating intervention thresholds.