*Purpose: The lung allocation score (LAS) was last revised in February, 2015, based on waitlist (WL) and posttransplant (PT) survival model cohorts from 2006-2008 and 2005-2008, respectively. The US policy goal of changing lung allocation to a continuous distribution framework precipitated the LAS cohort update.

*Methods: Updated LAS WL and PT survival models used patients, March 1, 2015-March 31, 2018. Each population was followed for 1 year. Cox proportional hazards models were fit using the covariates of the current LAS. We fit 2 sets of models: (1) all current LAS covariates, and (2) those remaining after removing unstable and non-predictive covariates. We computed LAS from each set of models for a snapshot of 1136 waitlist patients aged ≥12 years, January 1, 2019. We compared their rank ordering under current and updated LAS.

*Results: Updated models generated lower numbered ranks (increased access to transplant), for diagnosis group D and older candidates. In the updated cohort, adjusted risk of waitlist death was 4-fold higher for group D compared with group A, vs. 1.9-folder higher risk in the current model. The effect of age in the updated cohort was stronger than in the current cohort. Few patients aged <50 years had improved access with the updated LAS; most with improved access were aged ≥65 years (Figure). By diagnosis, only group D candidates experienced meaningfully improved access. Change in rank was examined for each removed covariate to determine if changes in transplant access changed due to newly excluded LAS variables. Removing diabetes status, cardiac index, central venous pressure, forced vital capacity, and functional status from the models had minimal impact on ranking. In our snapshot, <10 patients had obliterative bronchiolitis, serum creatinine increase of 150%, or bilirubin increase of 50%; impacts on these patients could not be generalized.

*Conclusions: Since 2008, the proportion of older and group D patients on the lung transplant waiting list has increased. This is reflected in the changes in predictors of WL and PT survival. Updating models with recent cohorts provided increased access to transplant for these more acutely ill patients.

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