Using GIS and Simulation for Analyzing Optimal Geographical Boundaries and Organ

描述（由申请人提供）：现有的器官移植研究报告了器官移植获取方面的各种差异。在种族、社会经济地位、保险类型和候选人居住地方面存在差异。虽然这些差异往往并存，但首先讨论的是与候选人所在地或“地理差异”相关的差异。为了解决这个问题，近年来人们讨论了重新绘制器官分布边界的重要性。然而，尚未探索出严格的重画方法。因此，我们的研究团队建议开发一个分析框架，通过应用一些涉及离散事件模拟（DES）和基于地理信息系统（GIS）的绘图的尖端技术来优化器官分配和边界创建。拟议的系统与现有系统在两个主要方面有所不同。首先，根据取肝位置和允许的最大冷缺血时间实时绘制边界。其次，除了当前系统中嵌入的其他政策目标之外，拟议的系统还最大限度地减少了接受器官的地域差异，例如优先考虑医疗紧迫性较高的候选人以及与可用器官的兼容性。这是一个多目标优化问题，其中两个或多个政策目标可能表现出权衡关系。将采用常用的加权方法来解决这个问题。作为主要的最终产品，研究团队打算为政策制定者提供一个基于GIS的交互式开放模拟网页，该网页可视化：（i）满足与器官分配相关的特定目标和条件的器官分配区域的地理边界，以及（ii）采用这种分配和边界系统的重要后果，特别是减轻器官移植获取方面的地理差异。拟议研究的主要兴趣是了解我们的系统科学技术开发的最佳器官分配系统如何实现更加公平和高效的器官分配系统。 尽管无论器官类型如何，器官分配的差异都很明显，但在肝移植中争议最大。因此，研究小组计划在拟议的研究中重点关注肝移植，尽管可以修改和扩展成功的模型以处理其他器官的分配系统。此外，我们将重点关注成人移植，尽管可以进行适当修改以建立儿童移植的等效框架。 公众健康相关性：虽然近年来人们讨论了重新绘制器官分布边界的重要性，但尚未探索出严格的重新绘制方法。我们的研究团队提出了一个使用地理信息系统和离散事件模拟的分析框架来识别这些边界并建立一个分配系统来减少每个边界内的地理差异。我们的工作有可能彻底改变美国的器官分配制度，使其更加公正和高效。

DESCRIPTION (provided by applicant): Existing studies of organ transplantation report various disparities in access. Disparities have been found in terms of race, socioeconomic status, insurance type and the location of candidate's residency. While these disparities tend to coexist, disparity associated with candidates' locations or "geographical disparity" is the first and foremost discussed. To remedy this, the importance of redrawing the organ distribution boundaries has been discussed in recent years. No rigorous method for redrawing has, however, been explored. Our research team thus proposes to develop an analytical framework for optimizing both organ allocation and boundary creation by applying some cutting-edge techniques involving Discrete Event Simulation (DES) and Geographic Information Systems (GIS) based mapping. The proposed system differs from the existing system in two main respects. First, the boundary is drawn real-time based on the location of liver retrieval and the maximum cold ischemia time allowed. Second, the proposed system minimizes geographical disparity in receiving an organ in addition to the other policy objectives embedded in the current system, such as prioritizing the candidates with a higher medical urgency and compatibility with the organ that became available. This is a multi-objective optimization problem in which two or more policy goals could exhibit trade-off relationships. The commonly-used method of weighting will be applied to solve this problem. As the main final product, the research team intends to provide policy makers with an interactive GIS-based open simulation webpage that visualizes: (i) geographical boundaries of organ distribution areas that meet specific objectives and conditions related to organ allocation, and (ii) important consequences of employing such an allocation and boundary system, in particular, alleviating geographical disparities in access to organ transplantation. The primary interest of the proposed research is to see how an optimal organ allocation system developed by our systems science technologies can achieve a more equitable and efficient organ allocation system. While the disparities in organ allocations have been evident irrespective of the type of organ, they are most disputed in liver transplants. The research team thus plans to focus on liver transplant in the proposed study although a successful model could be modified and extended to deal with the allocation systems of other organs. In addition, we will focus on the adult transplants although appropriate modifications could be made to establish an equivalent framework for pediatric transplants. PUBLIC HEALTH RELEVANCE: While the importance of redrawing the organ distribution boundaries has been discussed in recent years, no rigorous method for the redrawing has been explored. Our research team proposes an analytical framework using Geographical Information Systems and Discrete Event Simulations to identify such boundaries and build an allocation system that reduces geographical disparity within each boundary. Our work has the potential to revolutionize the system of organ allocation in the United States, making it more just and more efficient.