Performance of osteoporosis risk indices in a Japanese population

Background: Simple risk assessment questionnaires have been designed to inc rease awareness of osteoporosis and encourage the appropriate use of bone m ineral density (BMD) measurements. However, these tools were developed base d on populations that were primarily Caucasian or from other Asian countrie s, and their applicability to Japanese women is uncertain. Moreover, the BM D criterion for diagnosing osteoporosis in Japan (spinal BMD <70% of the yo ung adult mean) is different from that used in most other countries (BMD T scores : <less than or equal to>-2.5 or less than or equal to -2.0). Objective: The purpose of this study was to evaluate the ability of 4 exist ing osteoporosis risk assessment tools to identify women with osteoporosis (defined as spinal BMD <70% of the young adult mean) in a sample of postmen opausal Japanese women. Methods: Four osteoporosis risk indices-the Female Osteoporosis Self-Assess ment Tool for Asians (FOSTA), the Osteoporosis Risk Assessment Index, the S imple Calculated Osteoporosis Risk Estimation, and SOFSURF-were calculated in 1127 postmenopausal women aged 47 to 91 years enrolled in the Adult Heal th Study in Hiroshima. Spinal BMD was measured using dual-energy x-ray abso rptiometry to confirm or rule out osteoporosis. Results: The prevalence of osteoporosis increased with age, and one third o f all women aged; <greater than or equal to>70 years had osteoporosis. All 4 risk assessment tools performed similarly in identifying women with osteo porosis, with specificity between 38% and 43% when sensitivity was selected to be similar to 90%. Using 3 risk categories (high, intermediate, and low ) of the FOSTA, 43% of the high-risk women had osteoporosis as measured by BMD using the Japanese criterion, compared with only 24% and 5% of the inte rmediate-risk and low-risk women, respectively. Conclusions: The prevalence of osteoporosis is high among older Japanese wo men, as in other populations. The 4 indices evaluated performed well in cla ssifying the risk of osteoporosis among postmenopausal Japanese women. Appl ying these assessment tools may encourage appropriate use of BMD technology .