Lung transplantation in the United States, under oversight by the Organ Procurement Transplantation Network (OPTN) in the 1990s, operated under a system of allocation based on location within geographic donor service areas, wait time of potential recipients, and ABO compatibility. On May 4, 2005, the lung allocation score (LAS) was implemented by the OPTN Thoracic Organ Transplantation Committee to prioritize patients on the wait list based on a balance of wait list mortality and posttransplant survival, thus eliminating time on the wait list as a factor of prioritization. Patients were categorized into four main disease categories labeled group A (obstructive lung disease), B (pulmonary hypertension), C (cystic fibrosis), and D (restrictive lung disease/interstitial lung disease) with variables within each group impacting the calculation of the LAS. Implementation of the LAS led to a decrease in the number of wait list deaths without an increase in 1-year posttransplant survival. LAS adjustments through the addition, modification or elimination of covariates to improve the estimates of patient severity of illness, have since been made in addition to establishing criteria for LAS value exceptions for pulmonary hypertension patients. Despite the success of the LAS, concerns about the prioritization, and transplantation of older, sicker individuals have made some aspects of the LAS controversial. Future changes in US lung allocation are anticipated with the current development of a continuous distribution model that incorporates the LAS, geographic distribution, and unaccounted aspects of organ allocation into an integrated score.

美国的肺移植在 1990 年代在器官采购移植网络 (OPTN) 的监督下，在基于地理捐赠服务区域内的位置、潜在接受者的等待时间和 ABO 兼容性的分配系统下运作。2005 年 5 月 4 日，肺分配评分 (LAS) 由 OPTN 胸腔器官移植委员会实施，根据等待名单死亡率和移植后存活率的平衡，优先考虑等待名单上的患者，从而消除等待名单上的时间作为优先级因素。患者分为四个主要疾病类别，分别标记为 A 组（阻塞性肺病）、B 组（肺动脉高压）、C 组（囊性纤维化）、和 D（限制性肺病/间质性肺病），每组内的变量影响 LAS 的计算。LAS 的实施导致等待名单死亡人数减少，但移植后 1 年存活率没有增加。除了建立肺动脉高压患者的 LAS 值例外标准外，还通过添加、修改或消除协变量来改进对患者疾病严重程度的估计来进行 LAS 调整。尽管 LAS 取得了成功，但对年龄较大、病情较重的个体的优先排序和移植的担忧使得 LAS 的某些方面存在争议。预计美国肺分配的未来变化是当前发展的连续分布模型，该模型包含 LAS、地理分布、