b'2021 CARES Annual Report 41 41 Public Reporting of State Aggregate Metrics Survival after out-of-hospital cardiac arrest varies between regions in the United States. With the growing number of CARES state participants, there is a unique opportunity to present aggregate metrics by state to better understand OHCA incidence, survival outcomes, and bystander intervention rates nationwide. The table below shows aggregate metrics for state participants that had at least 50% population catchment in 2021. 18 states and the District of Columbia voluntarily agreed to participate in reporting these metrics.The included states have a wide range of both population catchment (606,347 to over 33 million) as well as incidence rate (44.2135.5 per 100,000; 3-fold difference). There was also marked variability in community interventions, with bystander CPR rates ranging from 25.872.0% (an almost 3-fold difference) and public AED use rates ranging from 3.616.3% (a more than 4-fold difference), as well as patient outcomes (overall survival: 4.614.6%; Utstein survival: 22.837.9%).Table 4. Public Reporting of State Aggregate Metrics, 2021. CARES sincerely appreciates the willingness of state participants to voluntarily share this information. Reporting of state-level variation in bystander intervention rates and patient outcomes validates the importance of data collection for OHCA, promotes the sharing of best practices and helps facilitate system improvements to save lives nationwide.'