Use of coefficient of variation in assessing variability of quantitative assays
Use of coefficient of variation in assessing variability of quantitative assays
复制标题
DOI：
10.1128/cdli.9.6.1235-1239.2002
复制
发表时间：
2002-11-01
期刊：
影响因子：
--
通讯作者：
Meade, BD
中科院分区：
文献类型：
--
作者：
Reed, GF;Lynn, F;Meade, BD
我们已经推导出了与定量测定的重复测量相关的变异系数与那些测量值对的预期分数之间的数学关系，所述测量值对的预期分数相差至少某个给定因子，即，由于测定变异性而非真实差异导致的不同结果的预期频率。了解这个频率有助于确定当特定的变异系数有效时，仅凭偶然就可以预期多大的差异。这个频率是可变性的操作指数，因为它表示在假设两个测量值测量相同的量的情况下观察到两个测量值之间特定差异的概率。因此，频率或概率成为评估测定是否足够精确的基础。该评估还提供了一个标准，用于确定同一受试者的两个检测结果（通过干预（如疫苗接种或感染）分离）是否与检测变化的预期差异更大，从而表明干预效应。来自国际合作研究的数据被用来说明这个拟议的解释的变异系数的应用，他们也提供了支持的数学推导中使用的假设。
We have derived the mathematical relationship between the coefficient of variation associated with repeated measurements from quantitative assays and the expected fraction of pairs of those measurements that differ by at least some given factor, i.e., the expected frequency of disparate results that are due to assay variability rather than true differences. Knowledge of this frequency helps determine what magnitudes of differences can be expected by chance alone when the particular coefficient of variation is in effect. This frequency is an operational index of variability in the sense that it indicates the probability of observing a particular disparity between two measurements under the assumption that they measure the same quantity. Thus the frequency or probability becomes the basis for assessing if an assay is sufficiently precise. This assessment also provides a standard for determining if two assay results for the same subject, separated by an intervention such as vaccination or infection, differ by more than expected from the variation of the assay, thus indicating an intervention effect. Data from an international collaborative study are used to illustrate the application of this proposed interpretation of the coefficient of variation, and they also provide support for the assumptions used in the mathematical derivation.