Bystander Defibrillation for Out-of-Hospital Cardiac Arrest in Public vs Residential Locations

Abstract

Importance: Bystander-delivered defibrillation (hereinafter referred to as bystander defibrillation) of patients with out-of-hospital cardiac arrests (OHCAs) remains limited despite the widespread dissemination of automated external defibrillators (AEDs).

Objective: To examine calendar changes in bystander defibrillation and subsequent survival according to a public or a residential location of the cardiac arrest after nationwide initiatives in Denmark to facilitate bystander-mediated resuscitative efforts, including bystander defibrillation.

Design, setting, and participants: This nationwide study identified 18 688 patients in Denmark with first-time OHCA from June 1, 2001, to December 31, 2012, using the Danish Cardiac Arrest Registry. Patients had a presumed cardiac cause of arrest that was not witnessed by emergency medical services personnel. Data were analyzed from April 1, 2015, to December 10, 2016.

Exposures: Nationwide initiatives to facilitate bystander resuscitative efforts, including bystander defibrillation, consisted of resuscitation training of Danish citizens, dissemination of on-site AEDs, foundation of an AED registry linked to emergency medical dispatch centers, and dispatcher-assisted guidance of bystander resuscitation efforts.

Main outcomes and measures: The proportion of patients who received bystander defibrillation according to the location of the cardiac arrest and their subsequent 30-day survival.

Results: Of the 18 688 patients with OHCAs (67.8% men and 32.2% women; median [interquartile range] age, 72 [62-80] years), 4783 (25.6%) had a cardiac arrest in a public location and 13 905 (74.4%) in a residential location. The number of registered AEDs increased from 141 in 2007 to 7800 in 2012. The distribution of AED location was consistently skewed in favor of public locations. Bystander defibrillation increased in public locations from 3 of 245 (1.2%; 95% CI, 0.4%-3.5%) in 2001 to 78 of 510 (15.3%; 95% CI, 12.4%-18.7%) in 2012 (P < .001) but remained unchanged in residential locations from 7 of 542 (1.3%; 95% CI, 0.6%-2.6%) in 2001 to 21 of 1669 (1.3%; 95% CI, 0.8%-1.9%) in 2012 (P = .17). Thirty-day survival after bystander defibrillation increased in public locations from 8.3% (95% CI, 1.5%-35.4%) in 2001/2002 to 57.5% (95% CI, 48.6%-66.0%) in 2011/2012 (P < .001) in residential locations, from 0.0% (95% CI, 0.0%-19.4%) in 2001/2002 to 25.6% (95% CI, 14.6%-41.1%) in 2011/2012 (P < .001).

Conclusions and relevance: Initiatives to facilitate bystander defibrillation were associated with a marked increase in bystander defibrillation in public locations, whereas bystander defibrillation remained limited in residential locations. Concomitantly, survival increased after bystander defibrillation in residential and public locations.

Conflict of interest statement

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr S. M. Hansen reports support by an unrestricted grant from the Danish Foundation TrygFonden. Dr C. M. Hansen reports support by an unrestricted grant from the Danish foundation TrygFonden, by Helse fonden, and by the Laerdal Foundation. Dr Kragholm reports receiving grants from the Laerdal Foundation and personal fees from Novartis. Dr Køber reports receiving personal fees from Novartis and Sanofi. Dr Torp-Pedersen reports consulting for Cardiome, Merck, Sanofi, and Daiichi Sankyo and receiving grants from Bristol-Myers Squibb. Dr Wissenberg reports support from the Danish Foundation TrygFonden, the Danish Heart Foundation, and the Health Insurance Foundation. No other disclosures were reported.

Figures

Figure 1.. Overview of Initiatives Undertaken in Denmark to Facilitate Bystander Resuscitative Efforts, Including Bystander Defibrillation

AED indicates automated external defibrillator; EMD, emergency medical dispatch.

Figure 2.. Flowchart Showing the Study Population With Out-of-Hospital Cardiac Arrest (OHCA)

EMS indicates emergency medical service.

Figure 3.. Bystander Defibrillation According to the Location of the Out-of-Hospital Cardiac Arrest (OHCA) and Registered Automated External Defibrillator (AED) Units

The proportion of patients with OHCAs who underwent defibrillation by bystanders according to the calendar year (2001-2012) in residential and public locations. Shaded areas indicate the number of registered AED units over time. Error bars indicate 95% CIs.

Figure 4.. 30-Day Survival According to the Location of the Out-of-Hospital Cardiac Arrest (OHCA) and Performance of Bystander Defibrillation

The 30-day survival among patients with OHCAs in public vs residential locations according to whether the patients underwent defibrillation by bystanders. The results from logistic regression were not adjusted for patient characteristics, and restricted cubic splines were used to model changes in calendar time. Shaded areas indicate 95% CIs.