Location of Cardiac Arrest Affects Likelihood of Bystander CPR

October 25, 2012

AURORA, Colorado — US researchers say much more work is needed to improve rates of bystander cardiopulmonary resuscitation (CPR) for an out-of-hospital cardiac arrest, as their new data show that the likelihood of a person receiving CPR depends on the median income and the racial composition of their neighborhood [1]. Dr Comilla Sasson (University of Colorado School of Medicine, Aurora) and colleagues analyzed surveillance data from 29 American cities and report their findings in the October 25, 2012 issue of the New England Journal of Medicine.

"The odds of receiving bystander-initiated CPR were approximately 50% lower in low-income black neighborhoods than in high-income nonblack neighborhoods," Sasson told heartwire . And even in high-income black neighborhoods, patients with out-of-hospital cardiac arrest "were approximately 23% less likely to receive bystander-initiated CPR than were patients in high-income nonblack neighborhoods.

We spend a ton of time documenting disparities, but we don't spend half as much time trying to fix them.

"We haven't done a very good job of getting CPR execution and awareness into the public mainstream for our black residents in the US, and I think there are a couple of different reasons," Sasson observes, noting that follow-up work her team has performed has helped provide information on this. Now they are hoping to effect change by going out into the community and educating people about how to perform hands-only CPR and, in turn, getting those people to educate their family and friends.

"I would love to see this replicated nationally and internationally," she says. "We spend a ton of time documenting disparities, but we don't spend half as much time trying to fix them. My dream is that, when you learn how to tie your shoelaces, you also learn what hands-only CPR is."

CPR Most Likely in High-Income White and Integrated Neighborhoods

Sasson and colleagues explain that more than 300 000 cases of out-of-hospital cardiac arrest occur in the US each year, and outcomes vary markedly, with survival rates ranging from 0.2% in Detroit to 16.0% in Seattle. The variation can be explained, in part, by different rates of bystander-initiated CPR. On average, bystanders administer CPR in less than one-third of all out-of-hospital cardiac arrests.

Prior studies have shown racial and socioeconomic disparities in the provision of bystander-initiated CPR, but it's not clear to what extent such disparities are due to neighborhood effects. And although a few studies have looked at the effect of neighborhood on bystander CPR, these were conducted within small geographic areas and therefore may not be generalizable to other settings, say the researchers.

They analyzed data from the multicenter Cardiac Arrest Registry to Enhance Survival (CARES) study, which at the time (2005–2009) incorporated 29 US cities. The neighborhood in which each cardiac arrest occurred was determined from census-tract data and classified on the basis of median household income per year: high-income (>$40 000) or low-income (<$40 000). An area was deemed "white" or "black" if more than 80% of the census tract was predominantly of one race. Neighborhoods without a predominant racial composition were classified as "integrated."

Among 14 225 patients with cardiac arrest, bystander-initiated CPR was provided to 4068 (28.6%).

As compared with patients who had a cardiac arrest in high-income white neighborhoods, those in low-income black neighborhoods were around 50% less likely to receive CPR from a bystander (odds ratio 0.49). The same was true of those with cardiac arrest in neighborhoods characterized as low-income white (OR 0.65), low-income integrated (OR 0.62), and high-income black (OR 0.77).

The odds ratio for bystander-initiated CPR in high-income integrated neighborhoods (1.03) was similar to that for high-income white neighborhoods.

"We found that on the individual level, people who were black or Latino or older were less likely to have someone stop and do CPR. Also, if you live in a poor neighborhood, your likelihood of getting someone to do CPR is significantly less than if you live in a white or integrated higher-income neighborhood," Sasson commented.

Identify the Barriers and Try to Overcome Them

Sasson explained that she and her team conducted a follow-up study in Columbus, OH, where they questioned focus groups of residents from poor black neighborhoods as to why they were not learning and performing CPR. "What we found was pretty interesting. There are a lot of different reasons," she notes.

First off, "people just couldn't afford to get even the most basic type of CPR certification, which costs $50 to $75," she says. "If they make less than $20 000 a year, it's a matter of 'Am I going to feed my kids tonight or am I going to get a CPR certification?' "

There's also a perception of danger, she explains. "People said, 'If I stop to help someone, they might try to mug me, and I don't want to put myself at risk.' Other concerns included 'If I do it wrong, am I going to get sued?' " And finally, many people 'just didn't want to breathe on some random person's mouth,' " she observes, but notes that this obstacle should now largely be overcome with the emphasis firmly on hands-only CPR.

One woman educated 20 participants in her Zumba class about how to do hands-only CPR. What we found is that this process is really empowering.

She explains that they then partnered with the local chapters of the AHA and American Red Cross to teach CPR. "We gave them CPR kits that had a DVD and an inflatable mannequin in them, and we taught them how to do hands-only CPR. What we found is that this process is really empowering. They were given the ability to teach family and friends a lifesaving skill, but most important, they were able to potentially save a life. One woman educated 20 participants in her Zumba class about how to do hands-only CPR."

Key to making this approach work is to make the CPR courses free and to identify organizations that are already working in these neighborhoods, she says.

And there is no reason, she says, why hands-only CPR cannot be taught in schools or be a requirement for getting a driver's license. "And wouldn't it be great if, while people were at the doctor's or in the security line at the airport, we could have a public-service announcement: 'Do you know what hands-only CPR is?' I think we would greatly increase the uptake of CPR provision in the community that way."

Sasson has no conflicts of interest. Disclosures for the coauthors are listed on www.nejm.org .