Out-of-hospital cardiac arrest (OHCA) patients have 1.9% lower risk-standardized survival rates at emergency medical service (EMS) agencies centered in Black and Hispanic catchment areas, compared with white catchment areas, a new study shows.

EMS response times, EMS termination of resuscitation and initiation of cardiopulmonary resuscitation or application of an automated external defibrillator by a first responder were not related to these survival rates, according to the study.

This information was reported by Anezi I. Uzendu, MD, of Saint Luke’s Hospital Mid America Heart Institute, Kansas City, Missouri, and the University of Missouri-Kansas City, and colleagues, in a manuscript published Tuesday online in JAMA: Internal Medicine.

EMS services and pre-hospital care are vital to the management of OHCA, and death rates from OHCA are greater in Black and Hispanic patients than white patients. Assessment of EMS agencies and management in Black and Hispanic communities may be different than EMS management in white communities.

The purpose of this system-level assessment was to investigate OHCA survival rates in EMS agencies serving catchment areas with primarily Black and Hispanic populations versus white populations. This study took place from Jan. 1, 2015, through Dec. 31, 2019, and data were analyzed between Aug. 17, 2022, and July 7, 2023. Data were obtained from the Cardiac Arrest Registry to Enhance Survival (CARES), which is a registry of OHCA cases in the U.S.

This cohort study included 377,475 nontraumatic OHCAs at 1,449 EMS agencies. Participants under 18 years old were excluded (n=10,356). The final cohort of participants included 258,342 people after going through exclusion criteria, and 764 EMS agencies were included in the final cohort.

The EMS agency areas were categorized as working catchment areas. defined as Black and Hispanic if they made up more than 50% of the area’s population, or white if they made up more than50% of the area’s population. The primary outcome of this study was agency-level risk-standardized survival rates (RSSRs) to hospital admission for OHCA at individual EMS agencies. Hierarchal logistic regression was used to calculate the RSSRs and compared between the EMS agencies serving Black and Hispanic or white patients.

Black and Hispanic catchment areas made up 10.7% of the EMS agencies (n OHCAs=258,342; median age=63.0 years [interquartile range {IQR}=52.0-75.0]; 36.1% women). Black and Hispanic catchment areas had significantly lower survival rates (overall mean RSSR=27.5%, standard deviation [SD]=3.6%; Black and Hispanic=25.8% [SD=3.6%]; white=27.7% [SD=3.5%]; p<0.001). A disproportionately higher number of the Black and Hispanic catchment areas were in the quartile with the lowest survival, and a lower number was in the quartile with the highest survival (32 agencies versus 12 agencies).

EMS response times, EMS termination of resuscitation rates and initiation of cardiopulmonary resuscitation or applying an automated external defibrillator by first responders were also assessed to observe potential differences between the catchment areas. No differences were found between Black and Hispanic versus white areas (mean [SD] RSSR post-adjustment=25.9% [3.3%] versus 27.7% [3.1%]; p<0.001).

Limitations of this study included a lack of generalizability to EMS agencies with a low volume of OHCA cases, such as rural areas. Additionally, Black and Hispanic communities have more comorbidities than white communities, so this could explain some of the outcomes. Data from EMS agencies and the CARES registry were also limited.

Overall, at EMS agencies working in catchment areas consisting mostly of Black and Hispanic patients, RSSRs for OHCA were 1.9% lower than the catchment areas consisting mostly of white patients. EMS response times, EMS termination of resuscitation and initiation of cardiopulmonary resuscitation or application of an automated external defibrillator by a first responder did not explain these results.

Source:

Uzendu AI, Spertus JA, Nallamothu BK, et al. Cardiac Arrest Survival at Emergency Medical Service Agencies in Catchment Areas With Primarily Black and Hispanic Populations. JAMA Intern Med. 2023 Sept 5 (Article in press).

Image Credit: Mr Doomits – stock.adobe.com