Table 1.

Characteristics of the Study Population.^*

Characteristic	Intervention (N = 820)	Control (N = 778)
Male sex — no. (%)	454 (55)	422 (54)
Age — yr
Median	60	60
Interquartile range	48–69	49–70
APACHE III score†
Median	67	67
Interquartile range	47–93	47–91
Interventions during stay in the ICU — no. (%)
Mechanical ventilation	338 (41)	300 (39)
Vasopressor administration	220 (27)	191 (25)
Hemodialysis	123 (15)	109 (14)
Source of admission — no. (%)
Emergency department or direct admission	383 (47)	367 (47)
Intrahospital transfer from general floor	295 (36)	306 (39)
Intrahospital transfer from another ICU	53 (6)	36 (5)
Interhospital transfer	89 (11)	69 (9)
Admission at night, 5:00 p.m.–4:59 a.m. — no. (%)	500 (61)	470 (60)

^*There were no significant differences (at P<0.05) between the intervention and control groups in any of the characteristics listed here.

^†APACHE III scores range from 0 to 299, with higher scores indicating more severe illness.