Diagnostic value of Osteoporosis Self-Assessment Tool for Asians (OSTA) and quantitative bone ultrasound (QUS) in detecting high-risk populations for osteoporosis among elderly Chinese men

This study aims to evaluate an osteoporosis self-assessment tool for Asians (OSTA) and quantitative bone ultrasound (QUS) and their combination in detecting populations at high risk for osteoporosis, and to determine the best cutoff value for the diagnosis of osteoporosis among elderly Chinese men. A group of Chinese men, aged a parts per thousand yen 60 years, recruited from the health checkup population of Zhongshan Hospital, Fudan University, were included. The OSTA index was calculated from age and weight. Bone mineral density (BMD) at left hip (femoral neck, internal, and total hip) and lumbar spine (L1-L4, L-Total) was measured with dual-energy X-ray absorptiometry (DXA), and calcaneal BMD was measured with QUS. Receiver operating characteristic analysis was used to determine the best cutoff values, sensitivity, and specificity. The area under the curve (AUC) between the different screening tools was compared. Our study included 472 men with mean age of 78.0 years. The prevalence of osteoporosis was 27.7 %.The best cutoff for OSTA was -3.5 for predicting men with osteoporosis at any site; this yielded a sensitivity and specificity of 47.3 % and 76.8 %, respectively. The AUC for OSTA was 0.676. The optimal cutoff for QUS-T score was -1.25, with a sensitivity of 80.4 % and specificity of 59.7 %. The AUC for QUS-T score was 0.762. Combining QUS with OSTA improved the specificity to 92.9 % but reduced sensitivity to 36.1 %. A new variable derived from a combination of OSTA and the QUS-T score gave a better performance, with sensitivity of 70.1 % and specificity of 72.1 %; the AUC for this variable was 0.771, which was greater than OSTA but not different from QUS alone. In conclusion, OSTA and QUS, respectively, and their combination may help find populations at high risk for osteoporosis, which could be an alternative method for diagnosing osteoporosis, especially in areas where DXA measurement is not accessible.