Table 1.

Published estimates of the annual incidence of SCD in the U.S.

Source	Definitional equivalents of SCA and/or SCD	Estimated annual incidence of SCD	Proportion of sudden deaths considered SCD	Method of estimation	Dates data collected for estimate	Publicati on Date
Gillum, RF(13)	SCD = sudden coronary death, defined as “deaths attributed to ischemic heart disease occurring out-of-hospital or in emergency rooms.”	223,864	56%	Based on national level data (from 40 states)	1980–1985	1989
Escobed o, et al.(14)	SCD = sudden coronary death, defined as “coronary heart disease deaths in persons dying within 1 hour of onset of cardiovascular symptoms.”	251,000	48%	Based on national level data (except Oregon)	1980 and 1986	1996
Zheng, et al.(17)	SCD = sudden cardiac death, defined as “the sudden, unexpected natural death from a cardiac cause a short time (generally ≤1 hour) after the onset of symptoms in a person without any previous condition that would seem fatal” or “any cardiac death occurring out of the hospital or taking place in the emergency room or dead on arrival in the emergency room.”	456,076	63.3%	Based on national level data	1989–1998	2001
Cobb, et al.(15)	All cardiac arrest cases with presumed cardiac etiology who received advanced life support from Seattle Fire Department emergency medical services.	184,000	NR	Extrapolated from community study (Seattle, Washington)	During specified periods between 1979–2000	2002
Chugh, et al 2004 (16) and Chugh, et al 2008 (19)*	SCD = sudden cardiac death, defined using the World Health Organization criteria as “sudden unexpected death either within 1 h of symptom onset (event witnessed), or within 24 h of having been observed alive and symptom free (unwitnessed).” Survivors of cardiac arrest were also included under SCD cases.	180,000– 250,000	NR	Extrapolated from community study (Multnomah County, Oregon)	2002–2003	2004
Nichol, et al 2008(18)	Cardiac arrest cases that occurred outside the hospital, were evaluated by EMS and either (1) received attempts at external defibrillation or chest compressions by organized EMS or (2) were pulseless but did not receive CPR or attempts to defibrillate by EMS.	294,851 (quasi confidence interval, 236,063 – 325,007)	NR	Extrapolated from 8 US sites (Alabama, Iowa, Dallas, Texas, Milwaukee, Wisconsin, Pittsburgh, Pennsylvania, Portland, Oregon, Seattle, Washington)	2006–2007	2008

CPR = cardiopulmonary resuscitation; EMS = emergency medical services; NR = not reported

^*A count estimate is not provided in Chugh, et al., 2004, but is extrapolated and reported in Chugh, et al., 2008.