Department of Medicine, Section of Pulmonary and Critical Care Medicine, University of Chicago, Chicago, Illinois; MacLean Center for Clinical Medical Ethics, University of Chicago, Chicago, Illinois.
Pritzker School of Medicine, University of Chicago, Chicago, Illinois.
J Heart Lung Transplant. 2022 Feb;41(2):217-225. doi: 10.1016/j.healun.2021.10.015. Epub 2021 Oct 28.
The United States (US) Lung Allocation Score (LAS) relies on the performance of 2 survival models that estimate waitlist and post-transplant survival. These models were developed using data from 2005 to 2008, and it is unknown if they remain accurate.
We performed an observational cohort study of US lung transplantation candidates and recipients greater than 12 years of age between February 19, 2015 and February 19, 2019. We evaluated the LAS waitlist and post-transplant models with the concordance probability estimate and by comparing predicted vs observed 1-year restricted mean survival times by risk decile. We then compared a nonparametric estimate of the observed LAS with the predicted LAS for each percentile of recipients.
The waitlist model ranked candidates (N = 11,539) in the correct risk order 72% of the time (95% CI 71%-73%), and underestimated candidate one-year survival by 136 days for the highest risk decile (p < 0.001). The post-transplant model ranked recipients (N = 9,377) in the correct risk order 57% of the time (95% CI 55-58%), and underestimated recipient one-year survival by 70 days for the highest risk decile (p < 0.001). Overall, the LAS at transplant explained only 56% of the variation in observed outcomes, and was increasingly inaccurate at higher predicted values.
The waitlist and the post-transplant models that constitute the LAS are inaccurate, limiting the ability of the system to rank candidates on the waitlist in the correct order. The LAS should therefore be updated and the underlying models should be modernized.
美国肺分配评分（LAS）依赖于两个生存模型的表现，这两个模型分别估计等待名单和移植后的生存率。这些模型是使用 2005 年至 2008 年的数据开发的，目前尚不清楚它们是否仍然准确。
我们对 2015 年 2 月 19 日至 2019 年 2 月 19 日期间年龄在 12 岁以上的美国肺移植候选人和受者进行了一项观察性队列研究。我们使用一致性概率估计和通过比较风险十分位数的预测与观察到的 1 年限制平均生存时间来评估 LAS 等待名单和移植后模型。然后，我们比较了每个百分位的受者的观察到的 LAS 与预测的 LAS 的非参数估计值。
等待名单模型以 72%（95%CI 71%-73%）的时间正确地对候选者进行了风险排序，并且对最高风险十分位数的候选者 1 年生存率低估了 136 天（p < 0.001）。移植后模型以 57%（95%CI 55%-58%）的时间正确地对受者进行了风险排序，并且对最高风险十分位数的受者 1 年生存率低估了 70 天（p < 0.001）。总体而言，LAS 仅解释了观察结果变异的 56%，并且在预测值较高时准确性越来越差。
构成 LAS 的等待名单和移植后模型不准确，限制了该系统正确对等待名单上的候选者进行排序的能力。因此，LAS 应该进行更新，并且底层模型应该现代化。
