Gu Xiangdong, Shapiro David, Hughes Michael D, Balasubramanian Raji
Division of Biostatistics and Epidemiology, University of Massachusetts, Amherst, MA, USA,
Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA,
R J. 2014 Jun;6(1):31-40.
Interval censored outcomes arise when a silent event of interest is known to have occurred within a specific time period determined by the times of the last negative and first positive diagnostic tests. There is a rich literature on parametric and non-parametric approaches for the analysis of interval-censored outcomes. A commonly used strategy is to use a proportional hazards (PH) model with the baseline hazard function parameterized. The proportional hazards assumption can be relaxed in stratified models by allowing the baseline hazard function to vary across strata defined by a subset of explanatory variables. In this paper, we describe and implement a new R package , for fitting a stratified Weibull model appropriate for interval censored outcomes. We illustrate the R package by analyzing data from a longitudinal oral health study on the timing of the emergence of permanent teeth in 4430 children.
当已知感兴趣的无声事件发生在由最后一次阴性诊断测试和首次阳性诊断测试时间确定的特定时间段内时，就会出现区间删失结局。关于区间删失结局分析的参数和非参数方法有丰富的文献。一种常用策略是使用参数化基线危险函数的比例风险（PH）模型。在分层模型中，可以通过允许基线危险函数在由一组解释变量定义的不同层之间变化来放宽比例风险假设。在本文中，我们描述并实现了一个新的R包，用于拟合适用于区间删失结局的分层威布尔模型。我们通过分析一项关于4430名儿童恒牙萌出时间的纵向口腔健康研究的数据来说明这个R包。
