Variation in fracture risk estimation among East Asian women.

Objectives: Bone mineral density (BMD) testing and fracture risk calculation help clinicians assess fracture risk and counsel patients. However, predicted fracture risks and outcomes for US East Asian individuals remain understudied.

Study Design: Retrospective cohort study.

Methods: Using standardized clinical profiles for East Asian women aged 70 years, fracture probabilities were estimated using the US Fracture Risk Assessment Tool (FRAX) version 4.1 and corresponding FRAX tools for East Asian countries. Next, clinical and BMD data from 3785 US Asian women aged 65 to 74 years were used to estimate 10-year hip fracture risk (US-Asian FRAX-v3.1) in comparison with actual observed 10-year hip fracture risk (Kaplan-Meier product limit estimate).

Results: For the same patient profile entered in the US-Asian FRAX and country-specific FRAX, the calculated 10-year hip fracture probability varied. Compared with the US-Asian FRAX calculator, the estimate was 2-fold higher using the Taiwan FRAX and Hong Kong FRAX, somewhat higher using the South Korea FRAX and Japan FRAX, and similar using the China FRAX. Among 3785 US Asian women (mean [SD] age, 69 [3] years), 23 experienced a hip fracture during a median follow-up of 6.8 years. Their observed 10-year hip fracture risk was 1.5% (95% CI, 0.8%-2.7%), and their median (interquartile range) predicted fracture probability (US-Asian FRAX-v3.1) was 1.1% (0.6%-2.0%).

Conclusions: Country-specific FRAX estimates varied between the United States and East Asian countries. For US Asian women, the US FRAX-predicted hip fracture probabilities were in the lower range of observed risk. Although these findings support the use of the US-Asian FRAX for hip fracture risk assessment in US East Asian women, further studies are needed, including the examination of Asian subgroups.