Table 1.

Patient demographics and hospital characteristics

Variables	Low (n=7940)	Intermediate (n=20 075)	High (n=5825)	P value
Age (years)
Mean±SD	54.1±13.6	57.5±14.2	58.6±13.7	<0.001
Female (%)	63.0	67.2	69.9	<0.001
Race (%)				0.386
White	56.8	57.9	55.1
Black	18.9	17.4	17.6
Hispanic	13.7	13.8	16.1
Other	10.5	10.9	11.2
Income quartile (%)				0.158
0–25th	30.5	29.7	30.8
26–50th	26.7	24.1	23.7
51–75th	22.3	25.7	25.2
76–100th	20.4	20.5	20.3
Admitted during weekend (%)	24.2	28.3	28.7	0.005
Healthcare coverage (%)				<0.001
Medicare	21.3	32.8	35.7
Medicaid	18.8	20.0	19.6
Private insurance	45.8	36.7	35.5
Other	14.1	10.5	9.2
Hospital demographics
Hospital region (%)				<0.001
Northeast	17.8	19.4	15.1
Midwest	17.5	18.3	22.9
South	42.8	40.0	36.7
West	21.9	22.3	25.3
Hospital bed size (%)				0.626
Small	5.0	4.9	5.4
Medium	18.1	16.7	18.3
Large	77.0	78.4	76.3
Hospital type (%)				0.618
Rural	0.3	0.1	0.3
Urban non-teaching	6.4	6.3	5.9
Urban teaching	93.3	93.5	93.8