Hypertensive disorders of pregnancy occur in about 10% of pregnant women around the world. Though there is evidence that hypertension impacts maternal cardiac functions, the relation between hypertension and cardiac dysfunctions is only partially understood. The study of this relationship can be framed as a joint inferential problem on multiple populations, each corresponding to a different hypertensive disorder diagnosis, that combines multivariate information provided by a collection of cardiac function indexes. A Bayesian nonparametric approach seems particularly suited for this setup and we demonstrate it on a dataset consisting of transthoracic echocardiography results of a cohort of Indian pregnant women. We are able to perform model selection, provide density estimates of cardiac function indexes and a latent clustering of patients: these readily interpretable inferential outputs allow to single out modified cardiac functions in hypertensive patients compared to healthy subjects and progressively increased alterations with the severity of the disorder. The analysis is based on a Bayesian nonparametric model that relies on a novel hierarchical structure, called symmetric hierarchical Dirichlet process. This is suitably designed so that the mean parameters are identified and used for model selection across populations, a penalization for multiplicity is enforced, and the presence of unobserved relevant factors is investigated through a latent clustering of subjects. Posterior inference relies on a suitable Markov Chain Monte Carlo algorithm and the model behaviour is also showcased on simulated data.
翻译:尽管有证据表明高血压影响孕产妇心脏功能,但高血压和心脏机能之间的关系只得到部分理解。对这种关系的研究可以被描述为对多个人群的共同推断问题,每个人群都对应不同的高血压紊乱诊断,这种诊断结合了由心脏病功能指数汇编提供的多种不同信息。巴耶斯非参数方法似乎特别适合这一设置,我们通过一个由印度孕妇群的反转体酸回声心动分析结果组成的数据集来证明它。我们能够进行模型选择,提供心脏功能指数的密度估计和病人的潜在聚集:这些容易解释的推断产出可以将高血压患者的经修改的心脏功能与健康科目相比单独列出,并逐渐增加与病症严重程度的改变。分析基于一种巴伊斯非参数模型,该模型依赖于新型的等级结构,称为对称等级分解分解过程。我们设计得当,以便确定非平均值,并在模型选择人群中的心脏功能指数指数指数指数和患者的潜在组合组合中提供密度估计:这些容易解释的推断产出结果使得高血压病人的心脏功能与健康对象相比,并逐步改变血管结构结构结构结构结构结构结构。在对人口进行精确的模型的模型上进行精确分析。