Z.W. Sollie1, E. Bryant2, J. Zhang1, P. Baliga3, S. Hanish3, B. Gibney1, B. Welch1, A. Kilic1 1Medical University Of South Carolina, Division Of Cardiothoracic Surgery, Department Of Surgery, Charleston, Sc, USA 2The Medical University Of South Carolina, College Of Medicine, Charleston, SC, USA 3The Medical University Of South Carolina, Division Of Transplant Surgery, Department Of Surgery, Charleston, SC, USA
Introduction:
Although transplant rates for end stage organ failure have been increasing in the United States, it is unclear if these trends are observed similarly across United Network for Organ Sharing (UNOS) geographic regions. The aim of this study was to evaluate temporal trends in transplant rates and compare these across UNOS regions.
Methods:
The UNOS database was queried to identify all isolated heart, lung, liver, and kidney waitlist candidates and transplants performed in adults ≥ 18 years old from January 1, 2013 to December 31, 2022. These were stratified primarily by the 11 UNOS regions and secondarily by organ type. Publicly available population data from the US census bureau by UNOS region for each year was collected. Ratios of both transplants per waitlisted candidates by region and transplants per population within the respective UNOS region were calculated for each year. Trendlines were created and correlation coefficients (r) were calculated. Trends were considered negative if p <0.05 and a negative r, unchanged if p-value was insignificant, and positive if p <0.05 and a positive r.
Results:
In total, 25,959 heart, 23,086 lung, 63,940 liver, and 135,679 kidney transplants were performed nationwide during this period. The distribution of correlations between number of transplants per waitlisted candidates and number of transplants per regional population over time are shown in figure 1. For correlations of transplants to waitlist candidates, lungs had the highest range of variability from -0.054 in region 6 to 0.86 in region 9 while hearts had the lowest from 0.552 in region 6 to 0.939 in region 9 (figure 1A). For transplants to regional population, hearts had the widest range of variability from -0.618 in region 4 to 0.973 in region 8 and kidneys had the lowest from 0.844 in region 6 to 0.981 in region 5 (figure 1B). Heart transplant had the most positive trends for transplants per waitlisted while lung transplant had the least (10 regions vs 2 regions) and kidney transplant had the most positive trends for transplants per population while lung transplant had the least (11 vs 6). In total 27 (61.36%) of the 44 region-organ combinations showed positive correlations in ratios of transplants per waitlisted patients and 33 (75%) showed positive correlations in ratios of transplants per total population over time.
Conclusion:
This study demonstrates an overall positive trend in the ratios of transplants performed for waitlisted candidate and for the adult population within UNOS regions. Despite this, there remains significant variability across UNOS regions. Further research aimed to identifying the causes of variability and efforts to improve geographic disparities is prudent.