Prediction based classification for longitudinal biomarkers.
Prediction based classification for longitudinal biomarkers.
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DOI：
10.1214/10-aoas326
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发表时间：
2010-09
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影响因子：
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通讯作者：
Montaner LJ
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文献类型：
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作者：
Foulkes AS;Azzoni L;Li X;Johnson MA;Smith C;Mounzer K;Montaner LJ
评估接受抗逆转录病毒治疗（ART）的HIV感染者循环CD 4计数随时间的变化是疾病监测的核心组成部分。越来越多的HIV感染受试者开始治疗，以及在资源有限的环境中支持CD 4计数检测的能力有限，这激发了人们对确定CD 4计数变化相关性（如总淋巴细胞计数等）的兴趣。建模技术的应用将是必不可少的，这是由于典型的非线性CD 4随时间的轨迹和多个输入变量捕获CD 4的变异性。我们提出了一种基于预测的分类方法，该方法涉及第一阶段建模和随后的基于临床有意义的阈值的分类。这种方法借鉴了受试者工作特征曲线文献中描述的现有分析方法，同时提供了用于处理连续结果的扩展。将该方法应用于独立的测试样品导致大于98%的CD 4计数变化的阳性预测值。预测算法是基于来自伦敦皇家自由医院的n = 270名HIV-1感染者的队列得出的，这些人从开始ART起被随访长达三年。使用由来自费城的n = 72名个体组成的测试样本进行验证，并随访类似的时间长度。结果表明，这种方法可能是一个有用的工具，优先有限的实验室资源，受试者开始抗逆转录病毒治疗后的CD 4检测。
Assessment of circulating CD4 count change over time in HIV-infected subjects on antiretroviral therapy (ART) is a central component of disease monitoring. The increasing number of HIV-infected subjects starting therapy and the limited capacity to support CD4 count testing within resource-limited settings have fueled interest in identifying correlates of CD4 count change such as total lymphocyte count, among others. The application of modeling techniques will be essential to this endeavor due to the typically non-linear CD4 trajectory over time and the multiple input variables necessary for capturing CD4 variability. We propose a prediction based classification approach that involves first stage modeling and subsequent classification based on clinically meaningful thresholds. This approach draws on existing analytical methods described in the receiver operating characteristic curve literature while presenting an extension for handling a continuous outcome. Application of this method to an independent test sample results in greater than 98% positive predictive value for CD4 count change. The prediction algorithm is derived based on a cohort of n = 270 HIV-1 infected individuals from the Royal Free Hospital, London who were followed for up to three years from initiation of ART. A test sample comprised of n = 72 individuals from Philadelphia and followed for a similar length of time is used for validation. Results suggest that this approach may be a useful tool for prioritizing limited laboratory resources for CD4 testing after subjects start antiretroviral therapy.