Changes in center-level use of HCV+ kidneys

To determine whether an increase in use of HCV+ kidneys was driven by a few aggressive centers or occurring across centers, we identified 173 kidney transplant programs that had performed at least 1 transplant per year over the study period and that were not pediatric centers (defined as performing >70% pediatric transplants). To estimate center-level clustering of HCV+ to HCV+ kidney transplants, we calculated the Gini coefficient per era, a dimensionless statistic between 0 and 1 that indicates clustering. In the context of this study, a Gini coefficient closer to 1 indicates that fewer centers performed the majority of HCV+ to HCV+ kidney transplants.