Table 4. Survival Outcomes in Studies Evaluating the Efficacy of Automated Electrical Defibrillators in Out-of-the Hospital Cardiac Arrest.

AED = automated external defibrillator; BS = bystander; CARES =Cardiac Arrest Registry to Enhance Survival; CPR = cardiopulmonary resuscitation; EMS = emergency medical services; FR = first responder; NIS = neurologically intact survival; OHCA = outside of hospital cardiac arrest

Investigator	Study Design	Sample Size	Study Comparison	Outcomes
Hansen et al.[29]	Retrospective (CARES Registry)	N = 4,961	Impact of providing focused training for BS and FRs on survival in OHCA	BS resuscitation had higher survival rates: EMS (CPR + Defibrillation)= 15.2% BS (CPR + Defibrillation)= 33.6% BS CPR + FR Defibrillation= 24.2% FR CPR + Defibrillation= 25.2%
Berdowski et al.[26]	Retrospective	N = 2,833	Onsite vs. dispatched AED on time to defibrillation and NIS to discharge	Onsite AED: 4.1 min, NIS 49.6% Dispatched AED: 8.5 min, NIS 17.2%
Blom et al.[28]	Retrospective	N = 6,133	Is NIS after OHCA due to AED use in those with initial shockable rhtyhms?	NIS: 29.1% (no AED) vs. 41.4% (with AED)
Capucci et al.[32]	Prospective	N = 3,366	AED use by FR vs. EMS on survival to discharge	Survival : FR (41.4%) vs. EMS: 5.9%
Ringh et al.[33]	Retrospective	N = 474	Defibrillation by FR vs. EMS on 1-month survival	1-month survival: FR with public AEDs (70%) vs. EMS 31%
Lijovic et al.[34]	Retrospective (Victorian Ambulance Cardiac Arrest Registry)	N = 2,270	AED use by BS vs. EMS on survival to discharge	Survival to discharge: 45% (BS) vs. 31% (EMS)
Nakahara et al.[19]	Retrospective (Japanese Nationwide OHCA Registry)	N = 167,912	Defibrillation by FR vs. EMS on NIS to discharge	NIS: 40.7% (BS) vs. 15% (EMS)
Hallstrom et al.[31]	Prospective, randomized public access defibrillation trial	N = 3,413	CPR only vs. CPR+AED by trained laypersons on survival to discharge following OHCA	23.4% (CPR+AED) vs. 14% (CPR only)
Agerskov et al.[25]	Retrospective (Mobile Emergency Care Unit and the Danish Cardiac Arrest Registry)	N = 521	30-day survival for AED application before and after EMS arrival	AED before EMS (64%) vs. after EMS arrival (37%); 15% OHCAs occurred within 100m of AED but only 3.8% had AED use
Weisfeldt et al.[35]	Prospective population based cohort study	N = 13,769	AED vs. no AED use before EMS arrival on survival to discharge	Survival: no AED (9%) vs. AED only (24%) vs. AED+shock (38%)
Eckstein et al.[27]	Prospective, longitudinal and observational study	N = 59	Impact of public access AED on survival to diacharge	Public access AED use = 69% NIS to discharge.