County Rankings Have Limited Utility When Predicting Liver Transplant Outcomes

Evidence of geographical differences in liver transplantation (LT) outcomes has been proposed as a reason to include community characteristics in risk adjustment of transplant quality metrics. However, consistency and utility of rankings in LT outcomes for counties have not been demonstrated.

We sought to evaluate the utility of county rankings (county socioeconomic status (SES) or county health scores (CHS)) on outcomes after LT.

Using the United Network for Organ Sharing Registry, adults ≥ 18 years of age undergoing LT between 2002 and 2014 were identified. County-specific 1-year survival was calculated using the Kaplan-Meier method for counties with ≥ 5 LT performed during this period. Agreement between high-risk designation by 1-year mortality rate and county ranking was calculated using the Spearman correlation coefficient.

The analysis included 47,769 LT recipients in 1092 counties. County 1-year mortality rates were not correlated with county CHS (Spearman ρ = 0.01, p = 0.694) or county SES (Spearman ρ = - 0.01, p = 0.734). After controlling for individual-level covariates, a statistically significant variability in mortality hazards across counties (p < 0.001) persisted. Although both CHS and SES measures improved the model fit (p = 0.004 and p = 0.048, respectively), an unexplained residual variation in mortality hazard across counties continued.

There is poor agreement between county rankings on various socioeconomic indicators and LT outcomes. Although there is variability in outcomes across counties, this appears not to be due to county-level socioeconomic indices.