b'442021 CARES Annual Report Findings from published CARES studies suggest that resuscitation care may differ at the individual- and community- level, with racial and socioeconomic factors influencing the likelihood that an individual receives bystander intervention (CPR or AED application) or survives an out-of-hospital cardiac arrest. Recognizing these disparities, high-risk areas can be identified, and community-based educational programs implemented. Quality improvement efforts aim to strengthen the links in the chain of survival: activation of the emergency response system, immediate and high-quality CPR, rapid defibrillation, advanced EMS resuscitation, and post-arrest care. Community-based interventions such as bystander CPR and public access defibrillation, if initiated before 911 responders arrive, can significantly improve OHCA survival.Chicago, the third largest and one of the most racially and socioeconomically diverse cities in the US, is one such success story, where the implementation of evidence-based interventions since 2011 has substantively improved OHCA outcomes. The city, previously known for low OHCA survival, has extensively reformed its approach to the treatment of OHCA by using data to guide improvements throughout the system of care, including (1) training EMS call takers and dispatchers from the Chicago Fire Department to improve recognition of OHCA and provide telephone-assisted CPR instructions to callers, (2) simulation-based training sessions defining high-performance CPR quality metrics and emphasizing high quality chest compressions with early defibrillation, and (3) joining CARES in order to systematically collect OHCA data and benchmark.17 Figure 5 below shows the implementation timeline of various interventions in the Chicago area alongside increased survival rates for all rhythms for the years 2013-2016. Figure 5. Observed rates for survival to discharge for the overall cohort and by shockable and nonshockable presenting rhythms. Increased survival rates were observed for all rhythms in close temporal association with the implementation of multiple pre-hospital interventions. Figure from Del Rios M et al. Large urban center improves out-of-hospital cardiac arrest survival. Resuscitation. 139:234-240. Reprinted with permission.Denver is another city that has utilized CARES data to tailor interventions to better meet the needs of high-riskpopulations. Its HANDDS (identifying High Arrest Neighborhoods to Decrease Disparities in Survival) program is changing the paradigm of community bystander CPR training, shifting away from a one-size-fits-all approach to one that isresponsive to community-specific needs and resources.18 The program uses a simple three-step approach: 1) identify high-risk neighborhoods, 2) understand common barriers to learning and performing CPR in these neighborhoods, and 3)implement and evaluate a train-the-trainer CPR Anytime intervention designed to improve CPR training in these communities. In the pilot trial, the community-based CPR educational program was tailored to the needs of specific racial,ethnic, and socioeconomic groups (e.g., Spanish-language training); was conducted in local settings based on communitypreferences (at churches and schools); and leveraged local resources (e.g. recruiting local bilingual residents as health educators). However, the results of this intervention have not yet been reported.17Del Rios M, Weber J, Pugach O, Nguyen H, Campbell T, Islam S, Stein Spencer L, Markul E, Bunney EB, Vanden Hoek T. Large urban center improves out-of-hospital cardiac arrest survival. Resuscitation. 139:234-240.18Sasson, C, Haukoos, JS, Eigel, B, & Magid, DJ. The HANDDS program: a systematic approach for addressing disparities in the provision of bystander cardiopulmonary resuscitation. Academic Emergency Medicine. 21(9), 10421049.'