Table 1. Demographics: Index events and mortality.

Factor	N	Survived Index Admission (N = 15,730)	In-Hospital mortality (N = 9,439)	p-value
Indicator of sex, % (95% CI)	25,170			0.15c
Male	13,208	51.9 (50.6, 53.2)	53.4 (51.9, 54.9)
Female	11,962	48.1 (46.8, 49.4)	46.6 (45.1, 48.1)
Primary expected payer (uniform), % (95% CI)*	25,132			<0.001 c
Medicare	12,501	46.4 (44.8, 47.9)	55.4 (53.3, 57.5)
Medicaid	4,944	21.2 (19.8, 22.6)	17.2 (15.7, 18.6)
Prvt. Ins/HMO	5,836	25.0 (23.6, 26.3)	20.3 (18.8, 21.9)
Self-pay	947.5	4.0 (3.4, 4.5)	3.5 (2.8, 4.1)
No Charge	106.7	0.52 (0.29, 0.75)	0.26 (0.08, 0.44)
Other	795.9	3.0 (2.6, 3.5)	3.4 (2.7, 4.1)
Patient Location: NCHS Urban-Rural Code, % (95% CI)*	25,093			0.55c
Large Central Metro	6,509	26.7 (24.2, 29.2)	24.7 (22.1, 27.2)
Large Fringe Metro	6,199	24.5 (22.0, 27.0)	25.0 (21.4, 28.6)
Medium Metro	5,132	20.0 (17.8, 22.3)	21.2 (18.7, 23.6)
Small Metro	2,464	9.9 (8.5, 11.2)	9.8 (8.3, 11.2)
Micropolitan	2,607	10.3 (8.9, 11.6)	10.6 (9.4, 11.8)
Noncore	2,181	8.6 (7.5, 9.7)	8.8 (7.2, 10.4)
Elective versus non-elective admission, % (95% CI)*	25,124			0.36c
No	23,095	91.7 (90.9, 92.5)	92.3 (91.1, 93.4)
Yes	2,029	8.3 (7.5, 9.1)	7.7 (6.6, 8.9)
Median household income national quartile for patient ZIP Code, % (95% CI)*	24,789			0.022 c
First quartile	7,990	32.9 (30.8, 34.9)	31.2 (28.7, 33.7)
Second quartile	6,442	26.6 (24.9, 28.3)	24.9 (22.9, 26.9)
Third quartile	5,890	23.0 (21.6, 24.4)	25.1 (23.3, 26.9)
Fourth quartile	4,465	17.5 (15.8, 19.3)	18.8 (16.7, 21.0)

*Data not available for all subjects, as unweighted frequencies: Primary expected payer (uniform) = 20; Patient Location: NCHS Urban-Rural Code = 48; Elective versus non-elective admission = 18; Median household income national quartile for patient ZIP Code = 214.

Frequencies presented are weighted counts. P-values:

^a = linear regression;

^b = linear regression with log transformation;

^c = Rao-Scott chi-square test.