Impact of Neighborhood Demographics on Out-of-Hospital Cardiac Arrest Outcomes
Understanding Out-of-Hospital Cardiac Arrest
In the United States, approximately 350,000 individuals experience an out-of-hospital cardiac arrest (OHCA) annually, with survival rates ranging from 8.3% to 10%. Research indicates that the neighborhood in which a patient resides can significantly influence the incidence of OHCA and the likelihood of survival.
Disparities in CPR Training and Bystander Response
There are notable disparities between white and black communities regarding the number of individuals trained in cardiopulmonary resuscitation (CPR). This disparity extends to the actual use of CPR by bystanders during OHCA events. Previous studies have yielded conflicting results about the relationship between an individual’s race and their chances of surviving an OHCA.
Researching the Neighborhood’s Role
Despite evidence showing lower bystander CPR rates in predominantly black neighborhoods, limited research has focused on how neighborhood racial composition affects bystander CPR, emergency medical services (EMS) response times, and overall patient outcomes. A recent study by Starks et al., published in JAMA Cardiology, sought to explore these relationships further.
Study Overview and Methodology
The retrospective observational study analyzed data from 22,816 non-traumatic OHCA patients collected by the Resuscitation Outcomes Consortium (United States) between 2008 and 2011. Neighborhoods where OHCA incidents occurred were categorized based on the percentage of black residents: less than 25%, 25% to 50%, 51% to 75%, and more than 75%.
Key Findings
Among the 22,816 participants, 3,069 experienced cardiac arrest in public, and 8,316 had a bystander witness the event. Out of these, only 9,012 received CPR from bystanders, while automatic external defibrillation was applied to 938 patients before EMS arrival. The study revealed that EMS response times and care processes varied based on neighborhood demographics. Specifically, predominantly black neighborhoods saw shorter response times.
Demographic Insights
Patients from neighborhoods with over 75% black residents tended to be younger, had a higher proportion of women, experienced OHCA less frequently in public, and initially presented with lower rates of shockable rhythms. The research identified an inverse relationship between the percentage of black residents and the likelihood of receiving bystander CPR or defibrillation. Additionally, survival to hospital discharge was notably lower for patients in predominantly black neighborhoods compared to those in mixed or majority black areas.
Limitations of the Study
The authors acknowledged that while the study establishes a correlation between neighborhood demographics and survival outcomes, it does not prove causation. The geographical location of patients across the United States also influences OHCA survival rates, and the study’s focus on racial composition may overlook other critical factors affecting patient outcomes.
Conclusions and Implications
The findings indicate that both the number of bystanders providing CPR and the overall survival rates of OHCA patients are significantly lower in neighborhoods with a higher percentage of black residents. However, in areas where black and white residents are equally represented, survival rates for both groups are comparable. This research underscores the importance of enhancing CPR education and developing strategies to increase bystander intervention in predominantly black neighborhoods.
Reference
Starks MA, Schmicker RH, Peterson ED, May S, Buick JE, Kudenchuk PJ, Drennan IR, Herren H, Jasti J, Sayre M, Stub D, Vilke GM, Stephens SW, Chang AM, Nuttall J, Nichol G; Resuscitation Outcomes Consortium (ROC). Association of Neighborhood Demographics With Out-of-Hospital Cardiac Arrest Treatment and Outcomes: Where You Live May Matter. JAMA Cardiol. 2017 Aug 30. doi: 10.1001/jamacardio.2017.2671.