Table II.

Factors Significantly Associated With Utilization of Emergency Medical Services in Patients Hospitalized With Acute Myocardial Infarction (AMI)

	Total Population		Patients With ST Segment Elevation AMI
Characteristic*	Adjusted O.R.	95% CI	Adjusted O.R.	95% CI
Age (years)
55-64	1.59	1.28,1.98	1.31	0.95,1.81
65-74	1.89	1.52,2.36	1.44	1.03,2.02
75-84	2.77	2.20,3.48	2.36	1.62,3.44
≥85	4.12	3.11, 5.47	2.95	1.74,4.99
Male	0.73	0.63,0.84	0.74	0.57,0.96
White	0.78	0.62,0.96
Prior DNR order	1.78	1.18,2.66
Symptoms
Chest pain	0.75	0.63,0.89	0.67	0.48,0.95
Abdominal pain	0.77	0.60,0.99	0.59	0.38,0.92
Arm/shoulder pain	0.75	0.61,0.91	0.58	0.43,0.79
Diaphoresis	1.49	1.28,1.73	1.39	1.10,1.77
Medical History
Diabetes	0.77	0.65,0.92
Heart failure	1.54	1.27,1.87
Stroke	1.33	1.06,1.66
AMI Characteristics
STEMI	1.30	1.11,1.52	--	--
Physiologic findings (at hospital admission) Systolic blood pressure (mmHg)
100-119	0.98	0.74,1.29	0.95	0.60,1.50
120-139	0.80	0.62,1.03	0.72	0.47,1.11
140-159	0.63	0.48,0.82	0.54	0.35,0.84
≥160	0.45	0.34,0.60	0.30	0.19,0.49
Laboratory findings (at hospital admission) Serum glucose (mg/dl)
120-139	0.99	0.82,1.20	0.87	0.63,1.19
140-159	1.13	0.91,1.42	1.18	0.81,1.71
160-179	1.61	1.24,2.09	1.43	0.93,2.20
180-199	1.41	1.04,1.92	1.25	0.77,2.03
≥200	1.71	1.38,2.11	1.53	1.05,2.24
Study Year
2003	1.37	1.10,1.72	1.46	1.01,2.12
2007	1.46	1.13,1.88	1.97	1.24,3.14
Time of Day
Morning	0.70	0.57,0.86
Afternoon	0.69	0.56,0.85

^*referent groups age<55 years, female, non-white race, absence of a prior DNR order, absence of selected acute symptoms, absence of selected comorbid conditions, Non-STEMI, weekday, systolic blood pressure <100 mmHg, serum glucose <120 mg/dl, study year of 1997, 12:00 a.m – 5:59 a.m.