The Impact of Geographical Distance on Survival in Adult Cystic Fibrosis Lung Transplant Recipients

Abstract

<h3>Purpose</h3> Cystic fibrosis (CF) remains one of the most common indications for bilateral lung transplantation (LTx) worldwide. Worse outcomes are seen after other organ transplantations than lung, for those living further from transplant centers. To date, the role of distance in lung transplantation outcomes in the United States (US) among people with CF has not been previously studied. The objective of this study was to assess the association of geographical distance with survival among adult CF LTx recipients in the US. <h3>Methods</h3> A retrospective nationwide cohort study of 2,838 adult CF LTx patients from 2005-2019 was conducted using the Scientific Registry of Transplant Recipients. Geographical distance was determined between the recipients' zip code and their transplant center zip code. Patients were stratified into 3 groups based on their distance (<50, 50-150, and >150 miles). The outcome of interest included time from transplantation to death or re-transplantation. All-cause mortality was examined with multivariable Cox proportional hazard regression, and the Kaplan-Meier method was used to model survival after LTx. <h3>Results</h3> Of the 2,838 CF LTx recipients, 1,218 (42.9%) traveled <50 miles; 814 (28.7%) traveled 50-150 miles; and 806 (28.4%) traveled >150 miles. During the study period, 1,170 (41.2%) patients died. There was a significant difference in survival by distance traveled (log-rank p=0.003). Compared to the recipients living within 50 miles of a transplant center, those traveling 50-150 miles (HR=1.20; 95% CI=1.02-1.41) and >150 miles (HR=1.29; 95% CI=1.10-1.52) had a higher risk of death. Younger age, being African American, having lower BMI, and less education had statistically significant negative associations with patient survival. Health insurance and year of transplantation were also found to have statistically significant associations with patient survival. <h3>Conclusion</h3> This study represents the largest cohort evaluating the effect of distance from transplant center on survival in adult CF LTx recipients. Worse survival was seen in patients living further away from their transplant center. Further investigation of the causes that contribute to this observed disparity may aid in improving survival rates of CF LTx recipients, including evaluating the number of clinic visits, transportation issues, cost of travel, or other financial concerns.