Reproducibility of bone mineral density measurement in daily practice
Reproducibility of bone mineral density measurement in daily practice
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DOI：
10.1136/ard.2002.005678
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发表时间：
2004-03-01
影响因子：
27.4
通讯作者：
Roos, JC
中科院分区：
文献类型：
--
作者：
Lodder, MC;Lems, WF;Roos, JC
背景：骨矿物质密度（BMD）测量经常对每个患者重复进行。随后的骨密度测量可以评估再现性。目的：探讨双能x线骨密度仪（DXA）测定骨密度的可重复性，并探讨不同可重复性测量方法在绝经后妇女中的实用价值。方法：95名女性，平均年龄59.9岁，随后进行了两次脊柱和髋关节骨密度测量。再现性用最小可检出差异（SDD）、变异系数（CV）和类内相关系数（ICC）表示。采用多水平分析对变异源进行了调查。结果：测量之间的中位数间隔为0天（范围0 - 45）。测量值（g/cm(2)）的平均差值（SD）分别为-0.001（0.02）和-0.0004（0.02）。在L1- 4和全髋关节，SDD （g/cm(2)）分别为+/- 0.05和+/- 0.04，CV（%）分别为1.92和1.59。脊柱和髋部ICC为0.99。结论：绝经后妇女的研究可重复性好。在重复DXA扫描中，骨密度变化超过2root2CV(%)，最不显著变化（LSC）或SDD应被视为显著。使用SDD比使用CV和LSC（%）更可取，因为它独立于BMD并且以绝对单位表示。以SDD表示，L1- 4的骨密度变化至少为+/- 0.05 g/cm(2)，全髋关节的骨密度变化至少为+/- 0.04 g/cm(2)，应被认为是显著的。
Background: Bone mineral density (BMD) measurements are frequently performed repeatedly for each patient. Subsequent BMD measurements allow reproducibility to be assessed.Objective: To examine the reproducibility of BMD by dual energy x ray absorptiometry (DXA) and to investigate the practical value of different measures of reproducibility in a group of postmenopausal women.Methods: Ninety five women, mean age 59.9 years, underwent two subsequent BMD measurements of spine and hip. Reproducibility was expressed as smallest detectable difference (SDD), coefficient of variation (CV), and intraclass correlation coefficient (ICC). Sources of variation were investigated by multilevel analysis.Results: The median interval between measurements was 0 days ( range 0 - 45). The mean difference (SD) between the measurements (g/cm(2)) was -0.001 (0.02) and -0.0004 (0.02) at L1- 4 and the total hip, respectively. At L1- 4 and the total hip, SDD (g/cm(2)) was +/- 0.05 and +/- 0.04 and CV (%) was 1.92 and 1.59, respectively. The ICC at spine and hip was 0.99.Conclusions: Reproducibility in the postmenopausal women studied was good. In a repeated DXA scan a BMD change exceeding 2root2CV (%), the least significant change (LSC), or the SDD should be regarded as significant. Use of the SDD is preferable to use of the CV and LSC (%) because of its independence from BMD and its expression in absolute units. Expressed as SDD, a BMD change of at least +/- 0.05 g/cm(2) at L1- 4 and +/- 0.04 g/cm(2) at the total hip should be considered significant.