Using MDPs to Optimize Living Donor Liver Transplants

描述(由申请人提供)： 在1990年前几乎闻所未闻的是，活体供体用于肝脏移植的使用一直在增加，现在每年有500多例移植。虽然活体供体移植有几个潜在的优点，但该程序将活体供体置于死亡和发病的风险中，因此，应尽可能适当和有效地进行。在这一探索性应用中，我们建议使用马尔可夫决策过程(MDP，这是专门为分析不确定条件下的顺序决策而设计的数学工具)来评估活体肝移植的最佳时机。这一开发中的R21应用的总体目标是对影响这一时机决定的因素提供洞察力，以便尽可能仔细和成功地做出移植决定。具体地说，这项工作旨在实现两个具体目标： 目的1：根据受体和供体的特点，评价活体供肝移植的最佳时机。接受活体捐献器官不在联合国操作系统的等候名单之外，不受外部分配和挑选规则的限制。因此，要做出的唯一决定是进行移植的适当时间(从临床健康状况下降的角度来看)。我们建议建立一个MDP来评估这个问题。 目的2：在接受活体供者移植之前，评估身体移植的最佳等待时间。由于有意愿的潜在活体捐赠者的存在并不排除列入身体等待名单，而且由于潜在的受赠者可能不想将该捐赠者置于致命风险中，更现实的问题是：“我应该在身体名单上等待多久才能接受活体捐赠者？”在目标1中开发的MDP将得到加强，以纳入顺序提供不同质量的身体器官的可能性。 这项工作具有创新性和发展性，因为MDP通常不被用于评估医疗决策，尽管它们是专门为评估不确定性下的顺序决策而开发的(这恰如其分地描述了临床医生做出的大多数决策)。研究团队在模拟肝脏疾病的进展和移植过程，以及将管理科学中的数学模型应用于健康和医学问题方面拥有丰富和独特的经验。我们寻求扩展我们在医学和工业工程之间成功合作的历史，调查这些复杂的数学模型在应用于真实和复杂的医疗决策时的有用性。

DESCRIPTION (provided by applicant): Virtually unheard of prior to 1990, the use of living donors for liver transplantation has been increasing and now represents over 500 transplants per year. Although living donor transplantation has several potential advantages, the procedure places the living donor at risk of death and morbidity and, therefore, should be undertaken as appropriately and efficiently as possible. In this exploratory application, we propose to use Markov decision processes, (MDPs, which are mathematical tools specifically designed to analyze sequential decisions under conditions of uncertainty) to evaluate the optimal timing of living donor liver transplantation. The overall goal of this developmental R21 application is to provide insights into the factors that affect this timing decision so that transplant decisions can be made as carefully and successfully as possible. Specifically, this work seeks to fulfill two specific aims: Aim 1: Evaluate the optimal time to transplant a living donor liver given the characteristics of the recipient and donor. Acceptance of a living donor organ occurs outside of the UNOS waiting list and is not subject to external allocation and selection rules. Therefore, the only decision to be made is the appropriate time (in clinical terms of declining health status) to conduct the transplant. We propose to build an MDP that will evaluate this question. Aim 2: Evaluate the optimal waiting time for a cadaveric transplant prior to accepting a living donor transplant. Because the existence of a willing potential living donor does not preclude listing on the cadaveric wait list, and because a prospective recipient may not want to place that donor at mortal risk, the more realistic question is: "How long should I wait on the cadaveric list before accepting a living donor?" The MDP developed in AIM 1 will be enhanced to incorporate the sequential possibility of being offered cadaveric organs of varying quality. The work is innovative and developmental as MDPs have not typically been used to evaluate medical decisions, even though they were specifically developed to evaluate sequential decisions under uncertainty (which aptly describes most decisions clinicians make). The investigative team has substantial and unique experience in modeling the progression of liver disease and the transplant process, and the application of mathematical models from management science to problems in health and medicine. We seek to extend our history of successful collaboration between Medicine and Industrial Engineering, to investigate the usefulness of these sophisticated mathematical models when applied to a real and complex medical decision.