32 Regional Variation in OHCA Outcomes There is marked regional variation in OHCA patient outcomes and bystander intervention rates. The diversity of CARES communities allows for comparison of system performance and outcome metrics. The figures below compare overall survival rates (Figure 22), Utstein survival rates (Figure 23), and bystander CPR rates (Figure 24) among the 125 EMS agencies with ≥150 CARES cases in 2017. These figures highlight the significant variability among participating agencies (ranges: overall survival 2.9 - 21.1% (7-fold difference in survival); Utstein survival 0 - 76.5%; bystander CPR 6.3 - 81.3% (12-fold difference in bystander CPR). The bars in each figure represent communities with an underlying patient population ranging from 100,000 to over 2 million. The red dotted line denotes the national average for benchmarking purposes (overall survival: 10.4%; Utstein survival: 32.6%; bystander CPR 38.2%). Figure 22. Variability in overall survival rates, among EMS agencies with ≥150 CARES cases in 2017. Figure 23. Variability in Utstein survival rates, among EMS agencies with ≥150 CARES cases in 2017. Figure 24. Variability in bystander CPR rates, among EMS agencies with ≥150 CARES cases in 2017.