Fracture risk assessed by Fracture Risk Assessment Tool (FRAX) compared with fracture risk derived from population fracture rates

Purpose: To evaluate the performance of the Swedish version of Fracture Risk Assessment Tool (FRAX)) without bone mass density (BMD) in a Danish population to examine the possibility of applying this version to Danish women. Methods: From the Danish National Register of social security numbers, we randomly selected 5000 women living in the region of Southern Denmark aged 40-90 years to receive a mailed questionnaire concerning risk factors for osteoporosis based on FRAX. The predicted 10-year probability of hip fractures was calculated for each woman returning a complete questionnaire using the Swedish version of FRAX. The observed 10-year hip fracture risk was also calculated for each woman using age-specific hip fracture rates from the National Hospital Discharge Register and National survival tables. Results: A total of 4194 (84%) women responded to the questionnaire and 3636 (73%) gave complete information and were included in the analysis. Using FRAX, the predicted 10-year fracture risk was 7.6%, ranging from 0.3 to 25.0% at the age of 41-50 and 81-90, respectively, while the corresponding observed fracture risk was 7.6%, ranging from 0.4 to 24.0%, respectively and not significantly different from the predicted risk (p = 0.92). Conclusions: The Swedish version of FRAX with out BMD is applicable to Danish women.