Abstract Sa401: Bystander Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest Cases in Chicago

Introduction: Bystander cardiopulmonary resuscitation (CPR) improves survival in out-of-hospital cardiac arrest (OHCA) cases. Nationally and locally, consistent efforts have been made in increasing awareness and training the public in CPR. In this study, we assessed the changes in bystander CPR rates over time, overall and by sex and race/ethnicity in Chicago. Methods: We analyzed OHCA cases served by Chicago Emergency Medical Services from 2014-2023. We excluded trauma cases, pediatric cases, cases that were missing bystander CPR information, cases from nursing homes and healthcare facilities, and cases from international airports. Average annual change was assessed along with a p-value for trend. Results: Of the 21,862 OHCA cases reported from 2014-2023, 58% were Black, 14% Hispanic and 24% White, and the remaining were categorized as other. Overall, the bystander CPR rate increased from 12.4% in 2014 to 43.9% in 2023. Yearly rates of bystander CPR improvement were initially inconsistent, but the rates have risen consistently since 2018 (with an average annual change of +5%, p=0.003). Similar trends have been seen by race/ethnicity and sex. In White cases, the bystander CPR increased from 19% to 47% from 2014 to 2023 (average annual change of +6.2% from 2020 onwards, p=0.047). In Hispanic cases, the bystander CPR increased from 17% to 51% from 2014 to 2023; however, the increase was not consistent from year to year. During the same time period, bystander CPR increased in Black cases from 8% to 41% (average annual change of +5.4% from 2018 onwards, p=0.001). From 2014 to 2023, bystander CPR increased from 15% to 44% (annual change of +4.8% from 2018 onwards, p=0.005) in males, and from 9% to 43% (annual change of +5.4% from 2018 onwards, p=0.004) in females. Conclusion: Bystander CPR rates have improved significantly in Chicago. Since 2020, sharp increase in bystander CPR rates is coinciding with overall improvement in OHCA survival in Chicago. The impact of bystander CPR on survival in different racial/ethnic groups requires further study.