Figure 1. Estimated Kaplan-Meier survival curves and estimated Cox proportional hazard ratios (HRs) by characteristics of transferring and receiving hospitals (2011 - 2020). Source: 100% FFS Medicare Claims, 2011 - 2020. The figure displays the Kaplan-Meier survival curves for STEMI patients who were transferred during a hospital stay. (a) Comparison of survival for patients transferred from PCI-capable and non-PCI-capable hospitals. (b) Comparison of survival for patients transferred from system and non-system hospitals. (c) Comparison of survival for patients transferred from rural and non-rural hospitals. (d) Comparison of survival for patients transferred to hospitals in the bottom and top deciles of 30-day risk-adjusted mortality among acute myocardial infarction patients. Each panel also shows the estimated adjusted HRs and 95% confidence intervals. HRs are adjusted for patient sex, age, Elixhauser comorbidity count, and a set of indicators for the year in which the stay occurred. FFS: fee-for-service; STEMI: ST-elevation myocardial infarction; PCI: percutaneous coronary intervention.