Background & Aims

Studies regarding acute-on-chronic liver failure (ACLF) among liver transplant (LT) candidates from the United Network for Organ Sharing (UNOS) database are being used to inform LT policy changes worldwide. We assessed the validity of identifying ACLF in UNOS.

Methods

We performed stratified random sampling among 3 US LT centers between 2013-2019 to obtain a representative patient sample across ACLF grades. We compared the concordance of ACLF classification by UNOS vs. blinded manual chart review, according to EASL-CLIF.

Results

Among 481 sampled LT registrants, 250 (52%) had no ACLF, 75 (16%) had ACLF grade 1, 79 (16%) had ACLF grade 2, and 77 (16%) had ACLF grade 3 per UNOS categorization. Concordance of ACLF grade by UNOS vs. chart review was: 72%, 64%, 56%, and 64% for no ACLF, grade 1, grade 2, and grade 3, respectively, with an overall Cohen’s kappa coefficient of 0.48 (95% CI 0.42–0.54). Absence of acute decompensation was the most common reason for overestimation, and discordant brain and respiratory failure categorization were the most common reasons for underestimation of ACLF by UNOS.

Conclusions

In this retrospective multi-center study, ACLF categorization by UNOS showed weak agreement with manual chart review. These findings are informative for ongoing allocation policy discussions, highlight the importance of prospective studies regarding ACLF in LT, and should encourage UNOS reform.

Lay summary

Acute-on-chronic-liver-failure (ACLF) is a specific and common form of liver failure associated with high death rates. Studies have been published using the United States transplant registry (UNOS) to identify and describe outcomes of transplant candidates and recipients with ACLF, and these data are driving policy changes for transplant allocation around the world, but nobody has shown whether these data are reliable. We found that UNOS was not categorizing ACLF in concordance or accurately when compared to chart review, which shows the need for UNOS reform and non-UNOS studies to appropriately inform policies regarding the transplantation of patients with ACLF.

中文翻译：

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器官共享联合网络数据库中慢性肝衰竭急性分类的不一致

背景与目标

来自联合器官共享网络 (UNOS) 数据库的关于肝移植 (LT) 候选人中慢性急性肝衰竭 (ACLF) 的研究正在被用来为全球 LT 政策变化提供信息。我们评估了在 UNOS 中识别 ACLF 的有效性。

方法

我们于 2013 年至 2019 年间在美国 3 个 LT 中心进行了分层随机抽样，以获得跨 ACLF 级别的代表性患者样本。我们根据 EASL-CLIF 比较了 UNOS与盲法手动图表审查对 ACLF 分类的一致性。

结果

根据 UNOS 分类，在 481 名抽样 LT 注册者中，250 名（52%）没有 ACLF，75 名（16%）有 1 级 ACLF，79 名（16%）有 2 级 ACLF，77 名（16%）有 3 级 ACLF。UNOS与图表审查的 ACLF 等级一致性为：无 ACLF、1 级、2 级和 3 级的情况分别为 72%、64%、56% 和 64%，总体 Cohen's kappa 系数为 0.48（95 % CI 0.42–0.54）。缺乏急性失代偿是高估的最常见原因，而不一致的脑和呼吸衰竭分类是 UNOS 低估 ACLF 的最常见原因。

结论

在这项回顾性多中心研究中，UNOS 对 ACLF 的分类与手动图表审查的一致性较差。这些发现为正在进行的分配政策讨论提供了信息，强调了关于 LT 中 ACLF 的前瞻性研究的重要性，并应鼓励 UNOS 改革。

外行总结

慢性肝衰竭（ACLF）是一种特殊且常见的肝衰竭形式，与高死亡率相关。已经发表的研究使用美国移植登记处 (UNOS) 来识别和描述 ACLF 移植候选者和接受者的结果，这些数据正在推动世界各地移植分配政策的变化，但没有人证明这些数据是否可靠。我们发现，与图表审查相比，UNOS 对 ACLF 的分类并不一致或准确，这表明需要进行 UNOS 改革和非 UNOS 研究，以适当地为有关 ACLF 患者移植的政策提供信息。