Comparing methods of measurement
Comparing methods of measurement
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DOI：
10.1111/j.1440-1681.1997.tb01807.x
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发表时间：
1997-02-01
影响因子：
2.9
通讯作者：
Ludbrook, J
中科院分区：
文献类型：
--
作者：
Ludbrook, J
1、比较连续生物变量的两种测量方法的目的是揭示系统差异，而不是指向相似性。2、测量方法之间的系统不一致有两个潜在来源：固定偏倚和比例偏倚。3.触发偏差意味着一种方法给出的值比另一种方法给出的值高（或低）一个常量。比例偏差是指一种方法给出的值比另一种方法给出的值高（或低），其数量与测量变量的水平成比例。4，必须假设，任何一种方法所做的测量都伴随着随机误差：在进行测量和生物变异.研究人员经常使用皮尔逊积差相关系数（r）来比较测量方法。这不能检测系统偏差，只有随机误差。6.研究人员有时使用最小二乘（模型I）回归分析来校准一种测量方法与另一种测量方法，在这种技术中，y值与直线的垂直偏差的平方和最小化，这种方法是无效的，因为y和x值都有随机误差。7.模型II回归分析迎合了随机误差与因变量和自变量都有关的情况。测量方法的比较就是这样一种情况。8.最小乘积回归是评论家分析模型II案例的首选技术。在这种情况下，x，y值与线的垂直和水平偏差的乘积之和最小化。9.最小二乘回归分析适用于校准一种方法与另一种方法，它也是一种灵敏的技术，用于检测和区分方法之间的激发偏倚和比例偏倚。另一种方法是检查方法之间的差异，以检测偏倚。这已被推荐给临床科学家，并已被许多人采用。11.这是审查员的意见，最少的产品回归技术是首选的，检查差异，因为前者区分固定和比例偏差，而后者没有。
1, The purpose of comparing two methods of measurement of a continuous biological variable is to uncover systematic differences not to point to similarities.2, There are two potential sources of systematic disagreement between methods of measurement: fixed and proportional bias. 3. Fired bias means that one method gives values that are higher (or lower) than those from the other by a constant amount. Proportional bias means that one method gives values that are higher (or lower) than those from the other by an amount that is proportional to the level of the measured variable. 4, It must be assumed that measurements made by either method are attended by random error: in making measurements and from biological variation.5. Investigators often use the Pearson product-moment correlation coefficient (r) to compare methods of measurement. This cannot detect systematic biases, only random error.6. Investigators sometimes use least squares (Model I) regression analysis to calibrate one method of measurement against another, In this technique, the sum of the squares of the vertical deviations of y values from the line is minimized, This approach is invalid, because both y and x values are attended by random error.7. Model II regression analysis caters for cases in which random error is attached to both dependent and independent variables. Comparing methods of measurement is just such a case. 8. Least products regression is the reviewer's preferred technique for analysing the Model II case. In this, the sum of the products of the vertical and horizontal deviations of the x,y values from the line is minimized.9. Least products regression analysis is suitable for calibrating one method against another, It is also a sensitive technique for detecting and distinguishing fired and proportional bias between methods.10. An alternative approach is to examine the differences between methods in order to detect bias. This has been recommended to clinical scientists and has been adopted by many. 11. It is the reviewer's opinion that the least products regression technique is to be preferred to that of examining differences, because the former distinguishes between fixed and proportional bias, whereas the latter does not.