Device-specific weighted T-score for two quantitative ultrasounds: operational propositions for the management of osteoporosis for 65 years and older women in Switzerland
Device-specific weighted T-score for two quantitative ultrasounds: operational propositions for the management of osteoporosis for 65 years and older women in Switzerland
复制标题
DOI：
10.1007/s00198-002-1358-z
复制
发表时间：
2003-03-01
影响因子：
4
通讯作者：
Krieg, MA
中科院分区：
文献类型：
--
作者：
Hans, D;Hartl, F;Krieg, MA
世界卫生组织（WHO）诊断骨质疏松症的标准主要适用于脊柱和髋关节水平的双能X线吸收测定法（DXA）测量。对更便宜、无电离辐射的设备的需求不断增长，例如有前途的定量超声（QUS）。与许多其他国家一样，瑞士越来越多地使用QUS测量，但没有足够的临床指南。DXA的T评分方法不能应用于QUS，尽管进行良好的前瞻性研究表明，超声可能是骨折风险的一个有价值的预测因子。因此，2000年，瑞士骨质疏松症防治协会（ASCO）授权一个名为瑞士质量保证项目（SQAP，其主要使命是在瑞士建立DXA和QUS的质量保证程序）的专家委员会，为在瑞士销售的两种QUS器械的骨质疏松症管理中使用QUS提出操作性临床建议。根据WHO对骨质疏松症的定义，基于骨质疏松性髋部骨折的风险以及髋部DXA骨质疏松症的预测，计算了Achilles的器械特异性加权“T评分”（Lunar，General Electric，麦迪逊，威斯康星州）。和撒哈拉（Hologic，Waltham，Mass.）超声波设备几项研究（总计数千例受试者）用于计算年龄校正的比值比（OR）和受试者工作曲线下面积（AUC），以预测骨质疏松性骨折（根据计算中涉及的研究设计考虑加权评分）。Achilles器械的OR分别为2.4（1.9-3.2）和AUC 0.72（0.66-0.77），Sahara器械的OR分别为2.3（1.7-3.1）和0.75（0.68-0.82）。为了将风险估计转化为临床应用的阈值，90%的灵敏度用于定义低骨折和低骨质疏松症风险，80%的特异性用于定义受试者为高骨折风险或髋部骨质疏松症。通过将骨折模型与髋部DXA骨质疏松模型相结合，我们发现硬度（Achilles）的T评分阈值为-1.2和-2.5，分别确定低风险和高风险受试者。同样，我们发现QUI指数（撒哈拉）的T得分为-1.0和-2.2。然后提出了一种结合QUS、DXA和临床因素的筛查策略，用于识别需要治疗的妇女。这种方法的应用将有助于最大限度地减少QUS的不适当使用，整个领域目前正受到影响。
The World Health Organization (WHO) criteria for the diagnosis of osteoporosis are mainly applicable for dual X-ray absorptiometry (DXA) measurements at the spine and hip levels. There is a growing demand for cheaper devices, free of ionizing radiation such as promising quantitative ultrasound (QUS). In common with many other countries, QUS measurements are increasingly used in Switzerland without adequate clinical guidelines. The T-score approach developed for DXA cannot be applied to QUS, although well-conducted prospective studies have shown that ultrasound could be a valuable predictor of fracture risk. As a consequence, an expert committee named the Swiss Quality Assurance Project (SQAP, for which the main mission is the establishment of quality assurance procedures for DXA and QUS in Switzerland) was mandated by the Swiss Association Against Osteoporosis (ASCO) in 2000 to propose operational clinical recommendations for the use of QUS in the management of osteoporosis for two QUS devices sold in Switzerland. Device-specific weighted 'T-score' based on the risk of osteoporotic hip fractures as well as on the prediction of DXA osteoporosis at the hip, according to the WHO definition of osteoporosis, were calculated for the Achilles (Lunar, General Electric, Madison, Wis.) and Sahara (Hologic, Waltham, Mass.) ultrasound devices. Several studies (totaling a few thousand subjects) were used to calculate age-adjusted odd ratios (OR) and area under the receiver operating curve (AUC) for the prediction of osteoporotic fracture (taking into account a weighting score depending on the design of the study involved in the calculation). The ORs were 2.4 (1.9-3.2) and AUC 0.72 (0.66-0.77), respectively, for the Achilles, and 2.3 (1.7-3.1) and 0.75 (0.68-0.82), respectively, for the Sahara device. To translate risk estimates into thresholds for clinical application, 90% sensitivity was used to define low fracture and low osteoporosis risk, and a specificity of 80% was used to define subjects as being at high risk of fracture or having osteoporosis at the hip. From the combination of the fracture model with the hip DXA osteoporotic model, we found a T-score threshold of -1.2 and -2.5 for the stiffness (Achilles) determining, respectively, the low- and high-risk subjects. Similarly, we found a T-score at -1.0 and -2.2 for the QUI index (Sahara). Then a screening strategy combining QUS, DXA, and clinical factors for the identification of women needing treatment was proposed. The application of this approach will help to minimize the inappropriate use of QUS from which the whole field currently suffers.