A two-part model for reference curve estimation subject to a limit of detection.
A two-part model for reference curve estimation subject to a limit of detection.
复制标题
用于受检测限制的参考曲线估计的两部分模型。
DOI：
10.1002/sim.4189
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发表时间：
2011
影响因子：
2
通讯作者：
Louis,GMBuck
中科院分区：
文献类型：
--
作者：
Zhang,Z;Addo,OY;Himes,JH;Hediger,ML;Albert,PS;Gollenberg,AL;Lee,PA;Louis,GMBuck
参考曲线通常用于识别具有临床相关变量极值的个体或自然依赖于年龄或成熟度的进展阶段。参考曲线的估计可能会因检测技术限制（LOD）而变得复杂，因为检测技术限制从左侧检查测量结果，就像我们对青春期开始前后男孩生殖激素水平的研究一样。我们在青春期激素研究的背景下讨论了LOD问题的常见方法，并提出了一个两部分模型来解决这些问题。该模型的一部分指定了测量值超出LOD的概率作为年龄的函数。模型的另一部分指定给定超过LOD的测量值的条件分布，同样作为年龄的函数。可将这两部分的资料结合起来，以估计参考曲线的可识别部分（即LOD以上），并计算给定测量值在LOD以上的相对位置。与LOD问题的一些常见方法不同，两部分模型没有涉及不可观察数量的不可测试假设，可以灵活地对可观察数据进行建模，并且易于使用现有软件实现。该方法以第三次全国健康与营养检查调查的激素数据为例。2011年由John Wiley & Sons出版。
Reference curves are commonly used to identify individuals with extreme values of clinically relevant variables or stages of progression which depend naturally on age or maturation. Estimation of reference curves can be complicated by a technical limit of detection (LOD) that censors the measurement from the left, as is the case in our study of reproductive hormone levels in boys around the time of the onset of puberty. We discuss issues with common approaches to the LOD problem in the context of our pubertal hormone study, and propose a two‐part model that addresses these issues. One part of the proposed model specifies the probability of a measurement exceeding the LOD as a function of age. The other part of the model specifies the conditional distribution of a measurement given that it exceeds the LOD, again as a function of age. Information from the two parts can be combined to estimate the identifiable portion (i.e. above the LOD) of a reference curve and to calculate the relative standing of a given measurement above the LOD. Unlike some common approaches to LOD problems, the two‐part model is free of untestable assumptions involving unobservable quantities, flexible for modeling the observable data, and easy to implement with existing software. The method is illustrated with hormone data from the Third National Health and Nutrition Examination Survey. Published in 2011 by John Wiley & Sons, Ltd.