I型区间删失数据下加速失效治愈率模型的估计问题
The Estimation of an Accelerated Failure Time Cure Model with Current Status Data
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摘要: 在治愈率模型中, 感兴趣的事件只发生在一部分个体上, 对另外的个体而言, 感兴趣的事件一直不会出现. 所有的个体被分为两类: 可治愈的个体和不可治愈的个体. 在寿命数据的研究中, 加速失效模型的研究成果很多, 但大多数是基于右删失数据进行的, 区间删失数据的研究成果相对较少, 特别是当研究总体包含有治愈的部分时. 本文研究的是I型区间删失数据下的一类加速失效治愈率模型. 假定协变量对个体被治愈的概率的影响用逻辑斯蒂克模型表示, 未治愈个体的发病时间用加速失效模型进行分析. 文中采用EM算法得出了模型参数的极大似然估计, 并用模拟计算的方式验证了估计量的有效性.Abstract: A cured model is a useful approach for analysing failure time data in which some subjects could eventually experience and others never experience the event of interest. All subjects in the test belong to one of the two groups: the susceptible group and the non-susceptible group. There has been considerable progress in the development of semi-parametric models for regression analysis of time-to-event data. However, most of the current work focuses on right-censored data, especially when the population contains a non-ignorable cured subgroup. In this paper, we propose a semi-parametric cure model for current status data. In general, treatments are developed to both increase the patients' chances of being cured and prolong the survival time among non-cured patients. A logistic regression model is proposed for whether the subject is in the susceptible group. An accelerated failure time regression model is proposed for the event time when the subject is in the non-susceptible group. An EM algorithm is used to maximize the log-likelihood of the observed data. Simulation results show that the proposed method can get efficient estimations.