Impact of Changes to the Lung Allocation System on Recipient Selection and Survival

Abstract

To examine the effect of the lung allocation system changes in 2017 on recipient selection and post transplant outcomes. Using the UNOS/SRTR database we identified all non multi-organ lung transplants from 7/1/16-3/31/19. Pre-change (Pre) and post-change (Post) groups were established based on the date of 11/25/17. The Pre and Post groups were compared with an analysis of variance and Chi-square test for continuous and categorical variables, respectively. Kaplan-Meier analysis and a Cox model were used to study survival. A multivariable model examined the effect on post operative extracorporeal membranous oxygenation (ECMO) at 72 hours. 3,254 and 3,339 lung transplants were identified in the Pre and Post groups respectively. The Post group donors and recipients were significantly older and had a higher lung allocation score and more commonly had restrictive lung disease (p<0.01). Unadjusted analyses demonstrated increased distance traveled, ischemic time, length of stay, and decreased 30 & 90 day survival (p< 0.01). The Post group had an increased use of ECMO after 72 hours (p<0.01; Table), however this effect was not significant on multivariable analysis. Kaplan Meier analysis demonstrated reduced survival at 1-year in the Post group (p<0.01; Figure) as did the Cox model (Hazard Ratio 1.37, 95% confidence interval [CI] 1.7-1.61; p<0.01). Changes to the lung allocation system have significantly increased travel and ischemic time for lungs, and appears to be associated with decreased survival at 1 year. Further investigation into the impact of policy change on practice behavior and outcomes is required.