Linkage Blocks	Number of Matched Records	Percent of Total Matched Records	Mean Weight for Matched Records
Block 1: In-hospital deaths and sudden cardiac death (ICD-9-CM 798.x)
Step 1: Admission Date, Gender, Age (Years), Facility	619	12.5%	60.45
Step 2: Admission Date, Gender, Date of Birth	511	10.3%	65.47
Step 3: Admission Date, Age (Years), Facility	16	0.3%	54.78
Step 4: Admission Date, Gender, Facility	318	6.4%	41.83
Step 5: Admission Date, Gender, Age (Years)	518	10.4%	46.09
Block 2: Cardiac arrest (ICD-9-CM 427.5)
Step 1: Admission Date, Gender, Age (Years), Facility	215	4.3%	59.98
Step 2: Admission Date, Gender, Date of Birth	47	0.9%	65.87
Step 3: Admission Date, Age (Years), Facility	2	0.0%	55.12
Step 4: Admission Date, Gender, Facility	21	0.4%	45.92
Step 5: Admission Date, Gender, Age (Years)	48	1.0%	51.50
Block 3: Ventricular tachycardia (427.1) and fibrillation (427.4)
Step 1: Admission Date, Gender, Age (Years), Facility	119	2.4%	61.77
Step 2: Admission Date, Gender, Date of Birth	34	0.7%	61.83
Step 3: Admission Date, Age (Years), Facility	1	0.0%	58.71
Step 4: Admission Date, Gender, Facility	108	2.2%	40.02
Step 5: Admission Date, Gender, Age (Years)	70	1.4%	38.97
Block 4: Acute myocardial infarction (410.x)
Step 1: Admission Date, Gender, Age (Years), Facility	76	1.5%	56.38
Step 2: Admission Date, Gender, Date of Birth	50	1.0%	54.70
Step 3: Admission Date, Age (Years), Facility	6	0.1%	57.28
Step 4: Admission Date, Gender, Facility	180	3.6%	41.34
Step 5: Admission Date, Gender, Age (Years)	92	1.9%	38.67
Block 5: Resuscitative procedures*
Step 1: Admission Date, Gender, Age (Years), Facility	6	0.1%	62.41
Step 2: Admission Date, Gender, Date of Birth	3	0.1%	63.82
Step 3: Admission Date, Age (Years), Facility	--	--	--
Step 4: Admission Date, Gender, Facility	5	0.1%	42.17
Step 5: Admission Date, Gender, Age (Years)	3	0.1%	37.03
Block 6: Enounters at any facility in CEMSIS data with restrictions**
Step 1: Admission Date, Gender, Age (Years), Facility	743	15.0%	51.28
Step 2: Admission Date, Gender, Date of Birth	--	--	--
Step 3: Admission Date, Age (Years), Facility	44	0.9%	48.12
Step 4: Admission Date, Gender, Facility	605	12.2%	48.52
Step 5: Admission Date, Gender, Age (Years)	--	--	--
Block 7: Encounters at any facility in CEMSIS data
Step 1: Admission Date, Gender, Age (Years), Facility	265	5.3%
Step 2: Admission Date, Gender, Date of Birth	--	--	--
Step 3: Admission Date, Age (Years), Facility	0	0.0%	n/a
Step 4: Admission Date, Gender, Facility	0	0.0%	n/a
Step 5: Admission Date, Gender, Age (Years)	--	--	--
TOTAL	4961	100.0%	52.10

CEMSIS = California Emergency Medical Services Information System

-- Step was not performed

^*Resuscitative procedures included: Cardiopulmonary resuscitation (99.60), Atrial cardioversion (99.61), Other electric countershock of heart (99.62), Closed chest cardiac massage (99.63), Carotid sinus stimulation (99.64), Other conversion of cardiac rhythm (99.69), Hypothermia (99.81)

^**Restrictions: ED records with a disposition of home were excluded. Records with an inpatient length of stay of shorter than three days, no cardiac arrest diagnosis, and survival to discharge were excluded.