Purpose: On 2/19/2015 major revisions to the Lung Allocation Score (LAS) calculation were made to more appropriately reflect candidates' waiting list urgency and post-transplant survival. Many of the revisions focused on reassessing the scores for lung candidates with pulmonary vascular disease (PVD). Pre- post- implementation analyses were constructed to evaluate the revisions.

Methods: OPTN data on adult lung-alone candidates and recipients were analyzed for a pre- and post- cohort between 2/19/14-2/18/16 split at the date of implementation. Waiting list data were used to determine the changes across diagnosis group pre- vs. post- implementation in LAS using a two-way ANOVA, and relative ranking on the waiting list relative to other diagnosis groups using a Wilcoxon Rank Sum Test. Transplant data were used to analyze changes in the number of transplants within each diagnosis group as well as Kaplan-Meier 1-yr recipient survival estimates overall and by diagnosis group.

Results: For adult lung-alone candidates in the pre- era (N=2,559) and the post- era (N=2,541) there were significant increases in the match LAS for PVD (p<0.001) and significant decreases for restrictive lung disease candidates (p<0.001). Similarly, a significant change was found in the relative ranking of candidates pre- vs. post- implementation for those with PVD (p<0.001), restrictive lung disease (p=0.012), and obstructive lung disease (p<0.001). There was a significant improvement in the 1-yr recipient survival estimate for the pre- (85.96%) vs. post- (89.41%) era (log rank test p<0.001). Recipients with a diagnosis of cystic fibrosis and immunodeficiency disorder and obstructive lung disease maintain the highest 1-yr survival estimates within both eras.

Conclusion: Overall, the revisions to the LAS are benefiting the targeted PVD candidates. Improvements were seen in the 1-yr recipient survival estimates for all patients. The OPTN Thoracic Organ Transplantation Committee will continue to monitor the revisions and assess whether any further modifications should be made to the LAS calculation.

CITATION INFORMATION: Lehman R., Carrico R., Uccellini K., Chan K., Whelan T. Impact of Changes to the LAS Calculation Am J Transplant. 2017;17 (suppl 3).

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