Despite Decreased Wait-List Times for Lung Transplantation, Lung Allocation Scores Continue to Increase

Abstract

In May 2005, the lung allocation score (LAS) was introduced as a means of allocating donor lungs in order to decrease wait-list mortality and prioritize candidates based on medical urgency and posttransplant survival. The purpose of this study was to assess changes in recipient wait-list times and mean LAS since the introduction of the LAS model. The United Network for Organ Sharing provided de-identified patient-level data. The study population consisted of all patients in the United States with a reported LAS (n = 3529) undergoing lung transplantation between May 7, 2005 and November 7, 2007. The study period was divided into 6-month intervals. The Kruskal-Wallis test was used to assess differences in variables with nonparametric distributions. The nonparametric trends test was used to determine significance of trends over time. There was a significant decrease in wait-list time during the study period, while LAS among transplant recipients increased (p < 0.001). There was no significant change in FVC (49.3 +/- 17.5%, p = 0.48) or pulmonary capillary wedge pressure (11.1 +/- 5.8 mm Hg, p = 0.23); however, there was a significant increase in age (51.5 +/- 13.9 years, p < 0.001) during the study period. When stratified by etiology, the LAS increased for both interstitial pulmonary fibrosis and COPD patients (p < 0.001). Moreover, the overall number of patients listed for transplantation as well as the LAS among transplant candidates increased (p < 0.001). Two years after initiation of the LAS model, wait-list times continue to decrease while mean LAS continued to increase. This increase in LAS among transplant recipients was observed most notably in patients with interstitial pulmonary fibrosis and COPD, and reflected in an increased mean LAS at the time of listing.