Diagnostic performance of quantitative ultrasound calcaneus measurement in case finding for osteoporosis in Thai postmenopausal women

Aim: Dual-energy X-ray absorptiometry (DXA) is currently considered the gold standard for the diagnosis of osteoporosis. Quantitative ultrasound (QUS) can be an alternative method that is less expensive, portable, and can be used at a primary care level to indicate osteoporosis in women. The present study aimed to assess the diagnostic performance of QUS calcaneus measurement in a case finding for osteoporosis in Thai postmenopausal women using DXA as a gold standard. Methods: Three hundred postmenopausal women, who had not menstruated normally for at least 1 year, were included in the study. To determine the accuracy and reliability of QUS of the calcaneus, calcaneus bone density measurement was carried out using the QUS and left femoral neck bone density was measured using DXA. Bone mass density (BMD) was interpreted as osteoporotic or normal using WHO criteria for determining the performance of QUS. Optimal cut-off values were determined using a receiver operating characteristic (ROC) curve for diagnosing the osteoporosis cases. Results: The number of osteoporosis cases in this study was 107 (35.67%). The sensitivity, specificity, positive and negative predictive values were 39.25%, 91.71%, 72.41%, 73.14%, respectively, when using the T-score of the WHO criteria as a reference. The positive and negative likelihood ratios were 4.73 and 0.66. When using the ROC curve to determine the optimal cut-off values, using the stiffness index of the QUS and categorizing age (<65 years and greater than or equal to65 years) before conducting the test, sensitivity and specificity were 77.6% and 59.6%, respectively. Conclusions: Bone mass density measurement for predicting osteoporosis using QUS had a very low sensitivity and was not good enough to replace the standard tool (DXA).