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获取器官的各种差异。在种族、社会经济地位、保险类型和候选人居住地方面发现了差异。虽然这些差异往往并存，但与候选人所在地或“地理差异”有关的差异是首先讨论的。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，没有严格的重绘方法被探索。因此，我们的研究小组建议通过应用一些涉及离散事件模拟（DES）和地理信息系统（GIS）的尖端技术，开发一个优化器官分配和边界创建的分析框架。拟议的制度与现行制度主要在两个方面有所不同。首先，根据肝脏取出的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外，拟议的系统最大限度地减少了接受器官的地域差异，例如优先考虑具有较高医疗紧迫性和与可用器官相容的候选人。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。我们将采用常用的加权法来解决这个问题。作为最终的主要产品，研究团队计划为政策制定者提供一个基于gis的交互式开放模拟网页，该网页可以可视化：(i)器官分布区域的地理边界满足与器官分配相关的特定目标和条件，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的地理差异。本研究的主要目的是研究如何通过我们的系统科学技术开发出一个最优的器官分配系统，从而实现一个更公平、更有效的器官分配系统。尽管器官分配的差异在不同类型的器官中都很明显，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，尽管一个成功的模型可以被修改和扩展到处理其他器官的分配系统。此外，我们将重点关注成人移植，尽管可以进行适当的修改以建立儿科移植的等效框架。

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.