Performance of kidney transplant programs in the United States is monitored and publicly reported by the Scientific Registry of Transplant Recipients (SRTR). With relatively few allograft failure events per program and increasing homogeneity in program performance, quantifying meaningful differences in program competency based only on 1-year survival rates is challenging.

We explored whether the traditional end point of allograft failure at 1 year can be improved by incorporating a measure of allograft function (i.e., eGFR) into a composite end point. We divided SRTR data from 2008 through 2018 into a training and validation set and recreated SRTR tiers, using the traditional and composite end points. The conditional 5-year deceased donor allograft survival and 5-year eGFR were then assessed using each approach.

Compared with the traditional end point, the composite end point of graft failure or eGFR <30 ml/min per 1.73 m² at 1-year post-transplant performed better in stratifying transplant programs based on long-term deceased donor graft survival. For tiers 1 through 5 respectively, the 5-year conditional graft survival was 72.9%, 74.8%, 75.4%, 77.0%, and 79.7% using the traditional end point and 71.1%, 74.4%, 76.9%, 77.0%, and 78.4% with the composite end point. Additionally, with the five-tier system derived from the composite end point, programs in tier 3, tier 4, and tier 5 had significantly higher mean eGFRs at 5 years compared with programs in tier 1. There were no significant eGFR differences among tiers derived from the traditional end point alone.

This proof-of-concept study suggests that a composite end point incorporating allograft function may improve the post-transplant component of the five-tier system by better differentiating between transplant programs with respect to long-term graft outcomes.

美国肾移植计划的实施情况由移植受者科学登记处 (SRTR) 进行监测和公开报告。由于每个项目的同种异体移植失败事件相对较少，并且项目绩效的同质性不断增加，因此仅根据 1 年生存率来量化项目能力的有意义的差异具有挑战性。

我们探讨了是否可以通过将同种异体移植物功能（即eGFR）的测量纳入复合终点来改善 1 年同种异体移植失败的传统终点。我们将 2008 年至 2018 年的 SRTR 数据划分为训练集和验证集，并使用传统端点和复合端点重新创建 SRTR 层。然后使用每种方法评估有条件的 5 年已故供体同种异体移植物存活率和 5 年 eGFR。

与传统终点相比，移植失败或移植后1年eGFR <30 ml/min/1.73 m ²的复合终点在基于长期死亡供体移植物存活的分层移植计划中表现更好。对于 1 至 5 级，使用传统终点的 5 年条件移植物存活率分别为 72.9%、74.8%、75.4%、77.0% 和 79.7%，使用传统终点时，5 年条件移植物存活率为 71.1%、74.4%、76.9%、77.0% 和 78.4 % 与复合终点。此外，对于从复合终点衍生的五层系统，与第一层的项目相比，第三层、第四层和第五层的项目在 5 年时的平均 eGFR 显着更高。派生的各层之间没有显着的 eGFR 差异仅从传统终点来看。

这项概念验证研究表明，结合同种异体移植功能的复合终点可以通过更好地区分移植方案与长期移植结果的关系来改善五层系统的移植后组成部分。