Application of the fracture risk assessment tool (FRAX^®) and determination of suitable cut-off values during primary screening in specific health check-ups in Japan

Specific health check-ups, which do not include osteoporosis screening, are conducted more frequently than periodic osteoporosis screening in Japan. In this study, we investigated the usefulness of the fracture risk assessment tool (FRAX^®) during specific health check-ups, evaluated the variations in its usefulness for 2 consecutive years, and determined FRAX^® cut-off values for osteoporosis screening. FRAX^® questionnaires were distributed to subjects who underwent specific health check-ups in 2009 and 2010 at Asahi-machi. Subjects who exhibited FRAX^® cut-off values of ≥10 % were advised to be screened at a medical institution. Bone mineral densities (BMDs) were measured in 201 subjects in 2009 and 105 subjects in 2010 after specific health check-ups, and treatment was initiated for 79 subjects in 2009 and 24 subjects in 2010. The number of subjects examined and the rate of treatment initiation following specific health check-ups were higher than those in subjects following periodic osteoporosis screening in 2009. However, the number and the rate following specific health check-ups dropped in 2010. According to receiver operating characteristic curves analyses, the sensitivity and specificity of FRAX^® to determine osteoporosis treatment were highest when the cut-off values were 8 % for men and 10.5 % for women. In conclusion, the combination of FRAX^® and specific health check-ups was more useful than periodic osteoporosis screening to narrow down the subjects and to motivate them to seek follow-up. Cut-off values for specific health check-up using FRAX^® should be approximately 8 % for men and 10.5 % for women