Can Weather Be a Factor in Liver Transplant Waitlist and Posttransplant Outcomes? Analysis of United Network for Organ Sharing Registry

Abstract

Cold climate is known to affect the frequency and attributable mortality of various illnesses. This study aims to evaluate the effect of climate among regions on liver transplant (LT) outcomes. We analyzed data from the United Network for Organ Sharing registry for 98,517 adult patients (aged ≥ 18 years) who were listed for LT between 2010 and 2019. During this period, 51,571 patients underwent single-organ, deceased LT. States were categorized based on their mean winter temperature: warm states (45°F-70°F), intermediate states (30°F-45°F), and cold states (0°F-30°F). Post-LT outcomes at 1 month, 1 year, and 3 years were compared using Cox proportional hazard models. Ninety-day and 1-year waitlist outcomes were compared among climate regions using Fine-Gray hazard regression model. After adjusting risks for recipient and donor characteristics, LT candidates in cold states had a significantly higher waitlist (90-day: subdistribution hazard ratio (HR) 1.46; 1-year: subdistribution HR 1.41; P < .001) and posttransplant mortality (30-day: subdistribution HR 1.23; P=.009, 1-year: subdistribution HR 1.16; P=.001; 3-year: subdistribution HR 1.08; P=.007). LT recipients in cold states had a higher proportion of deaths due to infections than warm states (cold states: 2.3%; intermediate states: 2.1%; and warm states: 1.7%; P < .001). Potential reasons include weather-related changes in the behavioral and physiological parameters of patients.