b'CARES is more than a registryits a quality improvement program dedicated to enhancing cardiac arrest outcomes. In 2024, over 2,600 EMS agencies and 2,200 hospitals contributed data, representing 174.1 million peopleover half the U.S. population. Together, were building a unified system for measurement, improvement, and survival. Every record strengthens the foundation for life-saving change. mycares.netIn Chicago, historical OHCA survival rates were alarmingly low, reported at just 2%, although even lower in some neighborhoods. To improve survival, a multidisciplinary collaborative was established in 2011. Leaders from institutions across Illinois united with the goal of ensuring that every cardiac arrest patient received state-of-the-art care at all stages. Chicagos participation in the CARES Quality Improvement Program in 2013 enabled detailed geographic analyses of OHCA incidents. The data identified communities with high OHCA incidence and low bystander CPR (BCPR) rates, prompting targeted interventions. Community engagement became central, with collaborations leading to culturally appropriate educational materials and training programs. These efforts resulted in a 10% increase in BCPR rates between 2014 and 2016. Further analysis revealed substantial progress across Chicagos census tracts, with fewer low BCPR neighborhoods and more areas with moderate to high rates. The citys BCPR rates improved from 15.5% in 2014 to 47.5% in 2022. The increased rates of bystander CPR contributed to more patients arriving at the hospital with a pulse, showcasing how CARES data and community engagement can drive meaningful improvements in OHCA survival rates. 5Figure 6. BCPR Rates of OHCA at Census Tract Level, Chicago Fire Department, Chicago, IL, CARES 2014, 2016, 2022. 57'