EMS Practices for OHCA Diverge Between Black/Hispanic, White Areas

Emergency medical services (EMS) agencies that serve predominantly Black/Hispanic areas differ in their approaches to out-of-hospital cardiac arrest (OHCA) compared with those serving mostly white populations, survey data show.

These discrepancies appear to explain at least some of the 2% survival gap seen between catchment areas with these racial/ethnic demographics, Paul S. Chan, MD (Saint Luke’s Mid America Heart Institute, Kansas City, MO), and colleagues, say in their Circulation: Cardiovascular Quality and Outcomes paper. Earlier research from the same group also has pointed to imbalances in survival after bystander CPR based on the patient’s race/ethnicity.

“We basically, using this survey, tried to better understand why there are differences in survival across paramedic agencies around the United States,” Chan told TCTMD, adding that they looked at factors like training, resources, and oversight in the hopes of finding what’s driving those inconsistencies. “If we could identify what those things are, if they were potentially modifiable, it might provide at least an avenue for thinking about how to address some of the disparities we see.”

One example, said Chan, is who’s first on the scene. In some regions, that person tends to be a police officer, but elsewhere paramedics or firefighters are the norm. Other elements include whether the person has the training to quickly recognize cardiac arrest and whether they have an automated external defibrillator (AED) on hand.

Survey Aimed at EMS Agencies

Between 2022 and 2023, researchers surveyed 577 EMS agencies around the United States taking part in the Cardiac Arrest Registry to Enhance Survival (CARES). In all, 470 agencies responded to the 67-item survey, whose questions spanned multiple domains: agency structure, characteristics of dispatch and first responders, EMS treatment of OHCA, data review and quality improvement activities, and community factors affecting bystander response to OHCA. Most often the surveys were completed by the EMS agency director.

All agencies handled at least 10 OHCAs annually between 2015 and 2019, with a total of 181,707 cases (mean age 62 years; 36.2% female) during that time. Most OHCAs (82.1%) occurred at home, 56.2% were witnessed by bystanders, and 20.6% had an initial shockable rhythm.

Ten percent of the participating agencies served predominately Black/Hispanic catchment areas, while the rest served majority white areas. There were no imbalances related to EMS staffing model (paid, volunteer, or hybrid) or type (fire- or hospital-based), dispatchers’ use of a standardized protocol for prearrival instructions, or provision of dispatcher-assisted CPR instructions.

Yet the survey did reveal numerous other differences between these two categories.

Key Differences in EMS Practices

Less involvement of police emergency response to OHCA in Black/Hispanic versus white areas is important, the study authors say, because “when police are part of [this effort], CPR may be initiated sooner, and there would likely be a higher number of available personnel to more effectively deliver continuous and effective CPR. In addition, the arrival of police first responders with vehicles equipped with an AED could decrease defibrillation time for shockable OHCAs.”

“A chicken-and-egg question” also was apparent in the data, Chan pointed out, in that Black/Hispanic catchment areas overall were more likely to have quality-improvement programs in place than were white areas. The reasons for that—namely, whether the programs were a response to poor quality or evidence of high quality—aren’t clear, he added.

Additionally, as in their prior study, the researchers found that people who experienced OHCA in majority Black/Hispanic areas had a 2% lower risk-standardized rate of survival to hospital admission compared with those in majority white areas (mean 26.0% vs 28.0%; P < 0.001).

Cardiac arrest is not super hard. It’s really all about teamwork and doing it well and doing it consistently. Paul Chan

The gap in survival was attenuated by around 30% when adjusting for practice differences among the two groups, which suggests more granular information might provide insights into the remaining disparity, Chan et al say.

Possible factors include structural inequities at the EMS level (eg, funding for training, personnel, and equipment) and the neighborhood level (eg, healthcare infrastructure and medical insurance). There also may be “barriers to accessing and activating emergency care in Black and Hispanic communities, including language (eg, delays in communicating with dispatchers or for dispatchers to initiate instructions for bystander CPR), immigration status, and fear of calling 9-1-1,” they suggest.

At a responder level, much of the difference between catchment areas, said Chan, comes down to “training and muscle memory of these core competencies, because cardiac arrest is not super hard. It’s really all about teamwork and doing it well and doing it consistently.”

The investigators stress, though, that the observational nature of their study precludes the ability to show a causal relationship between EMS practices and survival.

Chan said as a follow-up to this analysis, they’ve been visiting EMS agencies with the highest and lowest survival rates to better understand success stories—some of the groups serving Black/Hispanic communities have quite good results. The goal is to “try to parse out things that may be modeled by [other] agencies in the future in terms of improving survival gaps. . . . We’re excited about what we’re learning,” he said.