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: 9197041
• 负责人: DORRY L. SEGEV
• 金额: $ 63万
• 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/9197041
• 关键词: Accounting; Address; Area; Caring; Code; Congresses; Country; County; Event; Face; Goals; Heterogeneity; Incidence; Kidney; Kidney Transplantation; Laws; Liver; Liver diseases; Maps; Measures; Medical; Methodology; Modeling; Organ; Organ Donor; Organ Procurements; Organ Transplantation; Patients; Performance; Policies; Probability; Research; Risk; Services; Source; Staging; 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; organ procurement transplantation network; 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.

概括 国会在 1998 年规定，“居住地和列名地都不应成为 获得移植的机会”，但获得肾移植和肝移植的地理差异是一个主要问题 持续恶化的肾脏问题按等待时间进行分配，但存在 8 倍的差异。 捐赠服务区 (DSA) 的平均等待时间 肝脏将被运送给候选人。 最高 MELD（终末期肝病模型）评分，但 MELD 中位数相差 10 分 跨 DSA，对于具有高 MELD 的候选人，90 天的 LT 概率在 18%-86% 之间变化。 器官获取和移植网络（OPTN）于 2012 年一致决定“ 现有的分配地理差异……高得令人无法接受”，呼吁对优化系统进行研究。 很少提出临时修复方案，但很少探索优化策略，也没有全面的解决方案 甚至最近的两个重大政策变化Share-35和新肾也已经实施。 激烈的科学争论 关于器官可用性的地理差异是否真正是结构性的，还是仅仅反映了器官可用性的异质性 临床实践和器官获取组织的绩效导致了政策僵局。 我们已开始与 OPTN 肝脏委员会密切合作，设计优化的共享区， 将显着减少获取已故捐赠肝脏的地理差异。 目前，由于地理差异指标不佳以及供应和供应衡量指标未修正，工作受到限制。 此外，还有其他有前景的概念，例如重新划定 DSA 边界或动态优先级排序。 没有预先确定地图的候选者尚未被探索或评估，最后还没有开展任何工作。 这样做是为了适应为肝脏分配设计的优化模型，以适应肾脏分配的不同优先级。 我们将考虑临床实践，开发新方法，使移植更加公平 和分配系统。 为了移植政策，我们将隔离地理差异的根本驱动因素和有希望的轮廓 我们将讨论使全国候选人平等获得已故捐赠器官的政策。 目标如下： (1) 构建肝肾移植获得率的地理差异指标 (2) 衡量基本需求和供给 (3) 了解近期分配变化对临床决策和分配的影响 地理差异；以及 (4) 设计和测试减少地理差异的优化共享系统 同时明确考虑了供给需求的不确定性。拟议的研究直接解决了一个问题。 国会授权并使用 OPTN 青睐的方法将实现更公平的器官分配。 拯救生命并改善目前等待名单上面临死亡风险的 100,000 多名患者的护理。