FRAX™ and the assessment of Ten-Year Fracture Probability in Hong Kong Southern Chinese according to age and BMD Femoral Neck T-Scores

Abstract

At present, studies using Asian subjects to estimate the probability of osteoporotic fracture remain sparse. Although the WHO algorithms (FRAX™) risk assessment tool has data for Chinese population, the absolute fracture risk estimated for Chinese living in mainland China may not be applicable to southern Chinese in Hong Kong because of differences in lifestyle habits and subject characteristics. The objective of this study was to estimate the 10-year probability of osteoporotic fracture in Hong Kong southern Chinese according to age and BMD T-score at the femoral neck based on the methodology of FRAXTM risk assessment tool calibrated to the epidemiology of Hong Kong. Fracture data was obtained from the Clinical Data Analysis Reporting System (CDAS) of the Hospital Authority of Hong Kong while population size and death rates were taken from the Hong Kong Government Census and Statistics Department. Fracture probability was calculated using the cut-off values for T-scores derived from the NHANES III data for Caucasian women aged 20-29 years for BMD at the femoral neck. We found that the 10-year probability of osteoporotic fracture in Hong Kong southern Chinese men and women increased markedly with increasing age and decreasing femoral neck BMD T-score. Furthermore, the results showed that the 10-year absolute fracture risk for Hong Kong southern Chinese was substantially higher than the mainland Chinese and was comparable to Caucasians in other developed countries like USA and UK. Based on this evidence and until we have Hong Kong southern Chinese population-specific information, we recommend the application of the Caucasian risk profile to calculate the absolute fracture risk for Hong Kong southern Chinese subjects.