Appropriate FRAX® Intervention Threshold for Pharmacological Treatment of Osteoporosis in Thailand

Abstract

Purpose: The Fracture Risk Assessment Tool (FRAX®) has been recommended and incorporated into osteoporotic guidelines worldwide to assess fracture risk and promptly diagnose osteoporosis when bone mineral density is unavailable. However, a country-specific intervention threshold for Thai patients remains unknown. Therefore, we aimed to identify an appropriate cut-off point for the 10-year probability of hip fracture (HF), specifically in the Thai population. Methods: This retrospective cohort study included members of the Thai population aged 50-90 years, enrolled from January 2018 to January 2020. Analysis of data collected from online FRAX® tool questionnaires was conducted and the receiver operating characteristic (ROC) curve was used to determine a new appropriate cut-off value as the intervention threshold. Results: A total of 1,311 (HF: 422 [32.2%], non-HF: 889 [67.8%]) participants were included. The FRAX® 10-year probability of fracture in patients with HF was significantly higher than in non-HF (5.8% ± 4% vs. 4.7% ± 4.5%, respectively; P < 0.01), whereas the probability of major osteoporotic fracture (MOF) was similar (11.0 ± 5.8% vs. 10.6 ± 6.2%, P = 0.27). The ROC curve revealed a new intervention threshold for the FRAX®-based 10-year risk for HF of 4.3% with a maximum area under the curve (AUC) (95% confidence interval: 0.632 (range: 0.602-0.663; P < 0.001), with sensitivity and specificity of 62.9% and 60.7%, respectively. Conclusions: The intervention threshold cut-off value for osteoporosis treatment among the Thai population was 4.3%, which is higher than the cut-off point recommended in the Thai national guidelines.