Effect of Season and Climate Regions on Liver Transplant Waitlist Outcomes
Shamaa MT, Kitajima T, Ivanics T, Shimada S, Mohamed A, Rizzari MD, Collins KM, Yoshida A, Abouljoud MS, and Nagai S. Effect of Season and Climate Regions on Liver Transplant Waitlist Outcomes. J Am Coll Surg 2021; 233(5):S271.
J Am Coll Surg
Introduction: We previously reported that post-liver transplantation (LT) outcomes are worse in colder regions, possibly due to the effect of cold weather. The effect of cold climate on waitlist outcomes remains unknown. The aim of this study was to investigate the waitlist outcomes of LT candidates listed in cold states compared with warm states.
Methods: We analyzed the data from United Network for Organ Sharing registry for 98,965 adult patients (18 years or older) who were listed for single-organ, deceased LT between 2010 and 2019. Two seasons were defined: warm (April to October; n = 58,769) and cold (November to March; n = 40,196). States were categorized based on their mean winter temperature: cold states (0°F to 40°F) and warm states (40°F to 70°F). Waitlist outcomes at 90 days and 1 year were compared according to the season and states using the Fine-Gray hazard regression model.
Results: LT candidates listed in cold states were younger (median age 40 vs 43 years; p < 0.001), with lower median Model for End-Stage Liver Disease score (16 vs 17; p < 0.001), and were less likely to be on dialysis (7.6% vs 5.2%; p < 0.001) or require life support (3.7% vs 5.2%; p < 0.001) compared with warm states. In comparison with LT candidates listed in warm states, LT candidates listed in cold states had a significantly higher risk of waitlist mortality, lower chance of transplant probability, and recovery at 90 days and 1 year, even after adjusting for the season and patient characteristics at listing.
Conclusion: LT candidates had worse short-term and long-term waitlist outcomes when listed in cold states compared with warm states.