Yin-Ming Li a, b
aDepartment of Family Medicine, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
bDepartment of Public Health, Tzu Chi University, Hualien, Taiwan
Abstract
Objective
Osteoporosis is the most common generalized bone disease related to aging. The Osteoporosis Self-Assessment Tool for Asians (OSTA) risk index was developed to screen postmenopausal Asian women to identify women who should be evaluated with bone densitometry. In Taiwan, there is no report of the validity of the OSTA with dual energy X-ray absorptiometry (DXA) as a reference. In this study, we assessed the validity of the OSTA risk index and discuss its applications, using DXA of the lumbar spine as the gold standard.
Patients and Methods
Healthy subjects, aged 30–85 years, who were receiving a health check-up at a teaching hospital in eastern Taiwan were invited to participate in this study. All subjects gave their consent to analyze their data. A self-administered questionnaire was used to assess their demographic characteristics, and reproductive and medical histories. Bone mineral density of the posterior-anterior lumbar spine was measured by DXA, and a diagnosis of osteoporosis was made according to World Health Organization criteria. The sensitivity and specificity and their 95% confidence intervals (CIs) were calculated for the dichotomized OSTA risk index.
Results
This cohort consisted of 498 postmenopausal Taiwanese women, with a mean age of 60.3 ± 7.6 years and a mean weight of 57.9 ± 8.9 kg. Spinal DXA revealed that 35.9% were osteoporotic (with a T-score of £ −2.5). The OSTA risk index at the standard cut-off point of £ −1 had a sensitivity of 57.0% (95% CI: 52.7, 61.3) and a specificity of 69.3% (95% CI: 65.3, 73.4). Among women aged 60–70 years, the sensitivity, specificity, and accuracy of the OSTA risk index were 77.1% (95% CI: 63.7, 76.9), 49.2% (95% CI: 42.0, 56.4), and 64.9% (95% CI: 60.7, 69.8), respectively.
Conclusion
The OSTA risk index is a convenient but not a very sensitive tool to help target high-risk women aged 60–70 years for DXA testing. Clinical risk factors and the OSTA risk index should be combined to assess women aged £ 60 years. Further study of the validity of the OSTA risk index among elderly women with a larger sample size in different populations should be conducted with spinal and femur neck DXA testing as references.
Keywords
Osteoporosis; Postmenopausal women; Self assessment tool; Validity
