Table 1.

Characteristics of Patients According to Months of Admission to Major Teaching Hospitals

	Jul–Sep (N = 12,365)	Oct–Dec (N = 12,029)	Jan–Mar (N = 12,088)	Apr–Jun (N = 12,371)	P Value
Mean age, y ± SD	57 ± 19	58 ± 18	58 ± 18	58 ± 18	<.001
Male, %	54	54	52	53	<.01
Mean Apache III score ± SD	43 ± 27	43 ± 26	44 ± 27	43 ± 27	.26
Admission type, %
Nonoperative	58	58	58	57	.55
Postoperative	42	42	42	43
Comorbid conditions, %
AIDS	1.0	1.0	1.3	0.9	.17
Cirrhosis	11.7	10.4	13.5	11.7	<.001
Renal dialysis	5.3	5.3	5.2	4.9	.54
Hepatic failure	4.0	3.6	4.1	3.9	.69
Lymphoma	3.1	2.9	3.1	2.6	.55
Leukemia	3.4	3.0	3.4	3.7	.37
Solid tumor	14.4	13.5	14.0	14.2	.66
Immunosuppression	21.7	21.0	24.0	22.5	.01
1 Or more conditions	18.3	19.4	19.2	18.4	.05
2 Or more conditions	4.2	4.5	4.1	3.9	.19
Unadjusted mortality, %	13.9	14.7	14.8	14.2	.15
Mean ICU length of stay, d ± SD	4 ± 6	4 ± 6	4 ± 5	4 ± 5	.68
Mean hospital length of stay, d ± SD	14 ± 16	14 ± 15	14 ± 15	14 ± 14	.06
Admission source, %
Operating room	26.0	26.3	26.2	27.1	.20
Recovery room	17.5	17.0	16.8	16.8	.40
Emergency room	29.7	29.2	29.3	27.7	<.01
Hospital floor	5.3	5.3	5.2	4.9	.53
Other ICU in hospital	2.9	2.6	3.0	3.1	.06
Other hospital	5.3	5.5	5.2	5.5	.54
Other facility	3.6	3.8	3.8	3.9	.71
Non-ICU holding area	0.0	0.1	0.1	0.1	<.01

ICU, intensive care unit.