Panichkul Suthee, Sripramote Manit, Sriussawaamorn Narongchai
Department of Military and Community Medicine, Phramongkutklao College of Medicine, Bangkok, Thailand.
J Obstet Gynaecol Res. 2004 Dec;30(6):418-26. doi: 10.1111/j.1447-0756.2004.00224.x.
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.
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.
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 >or=65 years) before conducting the test, sensitivity and specificity were 77.6% and 59.6%, respectively.
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).
双能X线吸收法（DXA）目前被认为是骨质疏松症诊断的金标准。定量超声（QUS）可以作为一种替代方法，其成本较低、便于携带，可在基层医疗中用于指示女性骨质疏松症。本研究旨在以DXA作为金标准，评估在泰国绝经后女性中进行骨质疏松症病例筛查时，跟骨QUS测量的诊断性能。
300名至少1年未正常行经的绝经后女性纳入本研究。为确定跟骨QUS的准确性和可靠性，使用QUS进行跟骨骨密度测量，并使用DXA测量左股骨颈骨密度。根据世界卫生组织（WHO）用于确定QUS性能的标准，将骨密度（BMD）解释为骨质疏松或正常。使用受试者工作特征（ROC）曲线确定诊断骨质疏松症病例的最佳截断值。
本研究中骨质疏松症病例数为107例（35.67%）。以WHO标准的T值为参考时，灵敏度、特异度、阳性预测值和阴性预测值分别为39.25%、91.71%、72.41%、73.14%。阳性似然比和阴性似然比分别为4.73和0.66。当使用ROC曲线确定最佳截断值时，在测试前使用QUS的硬度指数并按年龄（<65岁和≥65岁）分类，灵敏度和特异度分别为77.6%和59.6%。
使用QUS预测骨质疏松症的骨密度测量灵敏度非常低，不足以替代标准工具（DXA）。
