标题： 多民族动脉粥样硬化研究（MESA）中的半参数零膨胀建模 显示英文标题

标题： Semiparametric zero-inflated modeling in multi-ethnic study of atherosclerosis (MESA)

摘要： 我们使用半参数零膨胀建模方法，分析了多民族动脉粥样硬化研究（MESA）中的冠状动脉钙化（CAC）的阿加森评分。该队列观察到的 CAC 评分包含高频零值和连续分布的正值。部分约束模型和无约束模型都被考虑用于研究从零到正、从小量到大量 CAC 发展的潜在生物学过程。 与现有研究不同的是，采用基于似然交叉验证的模型选择程序来确定最优模型，并通过比较蒙特卡洛研究证明了其合理性。 立方回归样条的收缩版本被同时用于模型估计和变量选择。在将所提出的方法应用于 MESA 数据分析时，我们表明影响 CAC 初始启动和当其为正值时的幅度的两种生物学机制可以通过无约束零膨胀正态模型更好地描述。我们的结果与已发表的研究显著不同，可能为进一步了解人类 CAC 发展的生物学机制提供新的见解。这一高度灵活的统计框架可以应用于其他领域的零膨胀数据分析。 显示英文摘要

摘要： We analyze the Agatston score of coronary artery calcium (CAC) from the Multi-Ethnic Study of Atherosclerosis (MESA) using the semiparametric zero-inflated modeling approach, where the observed CAC scores from this cohort consist of high frequency of zeroes and continuously distributed positive values. Both partially constrained and unconstrained models are considered to investigate the underlying biological processes of CAC development from zero to positive, and from small amount to large amount. Different from existing studies, a model selection procedure based on likelihood cross-validation is adopted to identify the optimal model, which is justified by comparative Monte Carlo studies. A shrinkaged version of cubic regression spline is used for model estimation and variable selection simultaneously. When applying the proposed methods to the MESA data analysis, we show that the two biological mechanisms influencing the initiation of CAC and the magnitude of CAC when it is positive are better characterized by an unconstrained zero-inflated normal model. Our results are significantly different from those in published studies, and may provide further insights into the biological mechanisms underlying CAC development in humans. This highly flexible statistical framework can be applied to zero-inflated data analyses in other areas.