Sepsis is a deadly condition affecting many patients in the hospital. Recent studies have shown that patients diagnosed with sepsis have significant mortality and morbidity, resulting from the body's dysfunctional host response to infection. Clinicians often rely on the use of Sequential Organ Failure Assessment (SOFA), Systemic Inflammatory Response Syndrome (SIRS), and the Modified Early Warning Score (MEWS) to identify early signs of clinical deterioration requiring further work-up and treatment. However, many of these tools are manually computed and were not designed for automated computation. There have been different methods used for developing sepsis onset models, but many of these models must be trained on a sufficient number of patient observations in order to form accurate sepsis predictions. Additionally, the accurate annotation of patients with sepsis is a major ongoing challenge. In this paper, we propose the use of Active Learning Recurrent Neural Networks (ALRts) for short temporal horizons to improve the prediction of irregularly sampled temporal events such as sepsis. We show that an active learning RNN model trained on limited data can form robust sepsis predictions comparable to models using the entire training dataset.

现代医疗保健系统正在对电子病历（EMR）进行连续自动监视，以识别频率越来越多的不良事件；但是，许多败血症等事件都没有明确阐明前瞻性（即事件链），可用于识别和拦截它的早期不良事件。目前，尚无可靠的框架来发现或描述不良医院事件之前的因果链。临床上相关和可解释的结果需要一个框架，可以（1）推断在EMR数据中发现的多个患者特征（例如，实验室，生命体征等）中的时间相互作用，并且（2）可以识别（s）的模式（s）。到即将发生的不良事件（例如，败血症）。在这项工作中，我们提出了一个线性多元霍克斯进程模型，并与$ g（x）= x^+$链接函数结合起来允许潜在的抑制作用，以恢复Granger Causal（GC）图。我们开发了一个基于两阶段的方案，以最大程度地提高可能性的替代品以估计问题参数。该两相算法可扩展，并通过我们的数值模拟显示有效。随后将其扩展到佐治亚州亚特兰大的Grady医院系统的患者数据集，在那里，合适的Granger Causal图识别出败血症之前的几个高度可解释的链。

Continuous, automated surveillance systems that incorporate machine learning models are becoming increasingly common in healthcare environments. These models can capture temporally dependent changes across multiple patient variables and can enhance a clinician's situational awareness by providing an early warning alarm of an impending adverse event such as sepsis. However, most commonly used methods, e.g., XGBoost, fail to provide an interpretable mechanism for understanding why a model produced a sepsis alarm at a given time. The ``black box'' nature of many models is a severe limitation as it prevents clinicians from independently corroborating those physiologic features that have contributed to the sepsis alarm. To overcome this limitation, we propose a generalized linear model (GLM) approach to fit a Granger causal graph based on the physiology of several major sepsis-associated derangements (SADs). We adopt a recently developed stochastic monotone variational inequality (VI)-based estimator coupled with forwarding feature selection to learn the graph structure from both continuous and discrete-valued as well as regularly and irregularly sampled time series. Theoretically, we develop a non-asymptotic upper bound on the estimation error for any monotone link function in the GLM. Using synthetic and real-data examples, we demonstrate that the proposed method enjoys result interpretability while achieving comparable performance to popular methods such as XGBoost.