36 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 138 EMS agencies with ≥150 CARES cases in 2018. These figures highlight the significant variability among participating agencies (ranges: overall survival 3.7–20.4% (5-fold difference); Utstein survival 5.6–71.4% (12-fold difference); bystander CPR 11.7–75.3% (6-fold difference). The bars in each figure represent communities with an underlying 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: 33.3%; bystander CPR 39.2%), while the grey vertical lines indicate quartile cutpoints. Figure 22. Variability in overall survival rates, among EMS agencies with ≥150 CARES cases in 2018. Figure 23. Variability in Utstein survival rates, among EMS agencies with ≥150 CARES cases in 2018. Figure 24. Variability in bystander CPR rates, among EMS agencies with ≥150 CARES cases in 2018.