Bystander CPR Laws Don't Only Work for Rich Areas

Government regulation was effective for increasing bystander CPR and public automated external defibrillator (AED) use even in a limited-resource setting, according to registry data from one Chinese city.

Shenzhen was among the Chinese pilot cities that debuted new out-of-hospital cardiac arrest (OHCA) initiatives in the last decade. On October 1, 2018, a new law there stipulated the use of AEDs and CPR training for the public and outlined legal responsibilities and resource allocation for OHCA rescues. By the end of 2022, approximately 3.7% of Shenzhen's over 17 million inhabitants had received emergency skills training.

Since implementation of this law, there have been significant improvements in rates of bystander-initiated CPR (from 4.1% to 18.7%, P<0.001) and AED use (from 4.1% to 5.3%, P<0.001) in bystander-witnessed OHCA, Qiang Zhou, MD, of the Shenzhen Center for Prehospital Care, and colleagues reported in JAMA Network Open.

"Furthermore, we identified not only an immediate increase in the rates of bystander CPR and AED use but persistent trends of increase in both rates during the months following implementation. These observations suggest that the interventions were practical and sustainable," study authors wrote.

These findings are particularly relevant to low-income and middle-income settings that may be more concerned about how to reasonably spend money and other resources to promote resuscitation strategies.

"In low-resource settings, the government can adopt a systemwide approach to implement resuscitation strategies and identify and correct the inefficiency caused by unclear division of responsibilities among health system departments," Zhou's group wrote. "This is very important for countries with limited resources because it can reduce the problem of increased CPR training costs caused by unclear division of responsibilities among health system departments."

Disparities in OHCA systems around the world suggest that lower-income countries have their work cut out for them.

Longstanding laws on bystander CPR and AED use seem to contribute to developed countries' relatively better OHCA outcomes, according to Zhou and colleagues, who contrasted the nearly 10% survival rate in the U.S. to the 1.2% rate in China historically.

They reported improved survival and other benefits since the 2018 Shenzhen law was implemented (all P<0.001):

• Prehospital return of spontaneous circulation (ROSC) rose from 0.9% to 7.2%
• Survival to arrival at the hospital boosted from 0.9% to 5.5%
• Survival at discharge increased from 0.6% to 2.8%

Nearly all these findings were significant in both multivariable logistic regression and multivariable Gaussian regression analyses. Only survival to discharge failed to meet the threshold for significance on the Gaussian analysis.

This may indicate that "efforts to improve bystander performance should be met with a commensurate in-hospital focus to optimize OHCA outcomes -- an equivalently challenging arena to address. In resource-limited settings, a generalizable next step from this investigation is to ensure accessible, durable, in-hospital processes evidenced to improve OHCA outcomes," commented Maxwell Hockstein, MD, of Georgetown University School of Medicine and MedStar Washington Hospital Center, D.C.

In an accompanying editorial, he emphasized the importance of supporting "all links in the chain" of care for OHCA and collecting neurological outcomes for survivors -- the latter notably lacking in the report by Zhou and colleagues.

"[W]e are reminded that the objective of improving bystander participation in OHCA is not to augment rates of [ROSC] in isolation. The goal of prehospital resuscitative efforts is to bolster sustained rates of neurologically favorable discharge from the hospital," Hockstein wrote.

The observational cohort study was based on Shenzhen registry data. Investigators identified 13,751 people with OHCA (median age 59 years, 73% men). They were roughly split between the approximately 57% with events in the period from January 2010 through September 2018 before the Emergency Medical Aid Act and the 43% whose cardiac arrest occurred after the law's enactment, from October 2018 through December 2022.

Inherent to its observational nature, the study design might have contributed to unmeasured confounding.

"For example, findings from study periods spanning disparate OHCA management practice patterns (e.g., targeted temperature management or coronary angiography) may be confounded by these factors, complicating interpretations," Hockstein noted.

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