Analysis of a nonsusceptible fraction with current status data
Analysis of a nonsusceptible fraction with current status data
复制标题
DOI：
10.1002/sim.3102
复制
发表时间：
2008-06-30
影响因子：
2
通讯作者：
Warkentin, Theodore E.
中科院分区：
文献类型：
--
作者：
Cook, Richard J.;White, Bethany J. G.;Warkentin, Theodore E.
在涉及亚临床事件的研究中，事件发生的时间通常会进行间隔删失，因为仅在检查时检测到事件发生。当个体在初始时间无事件并且进行单次后续检查时，获得当前状态数据。然而，在许多情况下，人群由易感和非易感亚群组成，其中只有易感个体会继续经历事件。然后，兴趣往往主要在于识别易感性的预后变量，其次是易感个体之间的事件时间分布。我们给出了一个简单的混合模型，便于估计易感个体的比例，协变量对易感性几率的影响，以及当前状态观察方案下的事件时间分布。基于Fisher信息，讨论了极大似然估计的渐近相对效率。EM算法提出的事件时间分布的参数，弱参数和非参数估计。该方法被应用于激励研究，检查接受骨科手术的患者对低分子量肝素的免疫反应。版权所有（C）2007约翰威利父子有限公司
In studies involving subclinical events, times of events are often subject to interval censoring since their occurrence is only detected at inspection times. When individuals are event-free at an initial time and a single follow-up inspection is made, current status data are obtained. In many settings, however, the population comprised a susceptible and a nonsusceptible subpopulation, where only susceptible individuals will go on to experience the event. Then interest often lies primarily in identifying prognostic variables for susceptibility, and secondarily in the event time distribution among the susceptible individuals. We give a simple mixture model that facilitates estimation of the proportion of susceptible individuals, covariate effects on the odds of susceptibility, and the event time distribution under a current status observation scheme. Asymptotic relative efficiency of maximum likelihood estimators is considered based on the Fisher information for a variety of settings. EM algorithms are proposed for parametric, weakly parametric, and nonparametric estimation of the event time distribution. The methods are applied to motivating studies examining an immunological response to low molecular weight heparin in patients undergoing orthopedic surgery. Copyright (C) 2007 John Wiley & Sons, Ltd.