Reducing geographic disparities in kidney and liver allocation

减少肾脏和肝脏分配的地理差异

• 批准号: 9337437
• 负责人: DORRY L. SEGEV
• 金额: $ 62.47万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9337437
• 关键词: Accounting; Address; Area; Caring; Code; Congresses; Country; County; Event; Face; Geography; Goals; Heterogeneity; Incidence; Kidney; Kidney Transplantation; Laws; Liver; Liver diseases; Maps; Mathematics; Measures; Medical; Methodology; Modeling; Organ; Organ Donor; Organ Procurements; Organ Transplantation; Patients; Performance; Policies; Probability; Research; Risk; Services; Source; System; Techniques; Testing; Time; Transplantation; Uncertainty; Variant; Waiting Lists; Work; clinical decision-making; clinical practice; design; geographic difference; improved; innovation; liver transplantation; model design; mortality; novel strategies; organ allocation; public health relevance; residence

Summary Congress dictated in 1998 that "neither place of residence nor place of listing should be a major determinant of access to a transplant," but geographic disparities in access to kidney and liver transplantation are a major problem that has persistently worsened. Kidneys are allocated by waiting time, but there are 8-fold differences in median waiting times across donation service areas (DSAs). Livers are intended to go to the candidate with the highest MELD (model of end-stage liver disease) score, but instead median MELD varies by 10 points across DSAs, and 90-day probability of LT for candidates with high MELD varies from 18%-86%. The Organ Procurement and Transplantation Network (OPTN) unanimously resolved in 2012 that "the existing geographic disparity in allocation… is unacceptably high," calling for studies of optimized systems. A few ad hoc fixes have been proposed, but optimizing policy has rarely been explored, and no comprehensive solution has ever been implemented. Even the two recent major policy changes, Share-35 and the new kidney allocation system (KAS), did not explicitly address geographic disparities. Clamorous scientific controversy over whether the geographic disparity in organ availability is truly structural or merely reflects heterogeneity in clinical practice and organ procurement organization performance contributes to the policy stalemate. We have started working closely with the OPTN Liver Committee to design optimized sharing districts that would significantly reduce geographic variation in access to deceased donor livers. However, this preliminary work is currently limited by poor metrics of geographic variation and uncorrected measures of supply and demand. Furthermore, other promising concepts, like redrawing DSA boundaries, or dynamic prioritization of candidates without pre-determined maps, have not yet been explored or evaluated. Finally, no work has been done to adapt optimization models designed for liver allocation to the different priorities of kidney allocation. We will develop new approaches to making transplantation more equitable, considering both clinical practice and allocation systems. Using an innovative adaptation of mathematical optimization and statistical inference to transplant policy, we will isolate the fundamental drivers of geographic disparity and outline promising policies to make deceased donor organs equally available to candidates across the country. We will address the following aims: (1) To construct metrics of geographic variation in access to liver and kidney transplantation that adjust for heterogeneity inherent to clinical practice; (2) To measure fundamental demand for and supply of organs; (3) To understand the impact of recent allocation changes on clinical decision-making and geographic disparities; and (4) To design and test optimized sharing systems that reduce geographic disparity while explicitly accounting for uncertainty in supply and demand. The proposed research directly addresses a Congressional mandate and uses the approach favored by the OPTN. More equitable organ distribution will save lives and improve the care of over 100,000 patients currently at risk of dying on the waiting list.

总结 国会在1998年规定，“居住地和上市地都不应是决定是否上市的主要因素。 获得移植”，但获得肾脏和肝脏移植的地理差异是一个主要问题， 这个问题一直在恶化。肾脏按等待时间分配，但有8倍差异 捐赠服务区（DSA）的平均等待时间。肝脏是打算去候选人与 最高MELD（终末期肝病模型）评分，但MELD中位数变化10分 在DSA中，具有高MELD的候选人的90天LT概率在18%-86%之间变化。 器官获取和移植网络（OPTN）在2012年一致决定，“ 现有的地理分配差距......高得令人无法接受”，要求对优化系统进行研究。一 提出了一些特别的修复措施，但很少探索优化策略，也没有全面的 解决方案曾经实施过。就连最近的两次重大政策变动，Share-35和新肾 分配制度（KAS）没有明确解决地域差异问题。喧嚣的科学争论 器官可用性的地理差异是真正的结构性差异，还是仅仅反映了 临床实践和器官采购组织的表现有助于政策僵局。 我们已经开始与OPTN肝脏委员会密切合作，设计优化的共享区， 将显著减少获取死亡供体肝脏的地理差异。然而，这一初步 目前的工作受到地理变化指标不佳和供应措施不正确的限制， 需求此外，其他有前途的概念，如重新划定DSA边界，或动态优先化 没有预先确定地图的候选人尚未进行探索或评估。最后，没有任何工作 这样做是为了使为肝脏分配设计的优化模型适应肾脏分配的不同优先级。 我们将开发新的方法，使移植更公平，考虑到临床实践和 和分配系统。使用数学优化和统计推断的创新适应 为了移植政策，我们将分离出造成地理差距的根本原因， 使全国各地的候选人都能平等地获得死者捐赠器官的政策。我们将解决 本研究的主要目的是：（1）建立肝肾移植地理差异的度量标准 调整临床实践固有的异质性;（2）测量基本需求和供应 （3）了解近期分配变化对临床决策的影响， 地理差异;（4）设计和测试优化的共享系统，减少地理差异 同时明确考虑到供需的不确定性。拟议的研究直接涉及一个 国会授权并使用OPTN青睐的方法。更公平的器官分配将 拯救生命，改善目前在等待名单上有死亡危险的10万多名病人的护理。