AHA: Statement on Bystander Intervention During Out-of-Hospital Cardiac Arrest

Woman with chest pain
Elderly woman having chest pains or heart attack in the park
The AHA issued a statement regarding the percentage of cases where bystander CPR is initiated and the need for more CPR training and education for the general public.

The American Heart Association (AHA) released a scientific statement in the journal Circulation about understanding the importance of lay response during out-of-hospital cardiac arrest (OHCA) events.

Individuals who have an OHCA are nearly twice as likely to survive when they receive cardiopulmonary resuscitation (CPR) from a witness while they wait for emergency personnel to respond. However, only 35% to 45% of people with OHCA worldwide receive CPR.

In the United States (US), less than 20% of people receive training in CPR or automated external defibrillator (AED) use annually. Preparing the general public to recognize the symptoms of sudden cardiac arrest, to contact emergency services, and to perform CPR is crucial to increasing survival and is therefore a public health problem.

Despite the importance of bystander intervention, there is a paucity of data which focuses on what calls a witness to action. The objective of this scientific statement was to review the current understanding of the bystander experience, likelihood of response, and residual impact of witnessing the OHCA event.

A meta-analysis of 19 studies comprising 232,703 OHCA patients found that CPR from a witness increased survival (odds ratio [OR], 1.95). Patients who received CPR were more likely to have initial shockable rhythm (80.9% vs 61.4%; P <.01) and to survive hospital discharge (18.3% vs 8.4%; P <.001). These associations were attributed to the pumping of blood to vital organs during CPR.

Response from bystanders varies by location and associates with socioeconomic, ethnic, population density, and gender factors. Although findings are conflicting, in general the older or less White the population is, the less likely bystanders are to intervene. In Los Angeles, Black and Latino individuals with OHCA received lay response CPR less than half as often as White individuals (OR, 0.47). In general, men are more likely to receive lay response CPR (OR, 1.27) than women.

The most common barrier for bystanders to intervene is lack of confidence in their skills. Additional barriers include panic, fear of infection or personal injury, and fear of litigation. Bystanders often (20%) report that it is difficult to remain calm enough to intervene and more than 40% of bystanders experience high levels of stress. Bystanders are more likely to intervene when they have a personal relationship with the individual. A random survey found that the probability of administering CPR was 85% for a family member and 51% for a stranger.

Among individuals who did respond, many expressed they had a positive experience and would perform CPR again if needed.

However, psychological sequelae can occur after administering CPR. Many responders report feeling numb, tired, and if not successful, self-blame after their intervention. The potential harm of intervening is not insignificant, and some individuals go on to experience post-traumatic stress disorder (PTSD)-type symptomology, with nearly twice as high PTSD scores than other witnesses who did not intervene.

The AHA statement authors wrote that there is a need for improving the readiness of future responders, to train more of the general public in CPR skills, and to formulate a debriefing protocol to decrease risk for PTSD.

Disclosure: Multiple authors declared affiliations with industry. Please refer to the original article for a full list of disclosures.


Dainty KN, Colquitt B, Bhanji F, et al. Understanding the importance of the lay responder experience in out-of-hospital cardiac arrest: A scientific statement from the american heart association. Circulation. Published online March 12, 2022. doi:10.1161/CIR.0000000000001054