Table 1.

Characteristics of admissions with a diagnosis of AKI according to day of admission on the basis of NIS data from 2003 to 2006

WeekendWeekdayP Value
Number of admissions214,832748,898
Age, mean (SD), years69.4 (16.8)69.2 (16.5)<0.001
Women, n (%)103,705 (48.3)357,701 (47.8)<0.001
Race, n (%)<0.001
    white109,110 (50.8)387,325 (51.7)
    black29,272 (13.6)97,467 (13.0)
    Hispanic14,923 (6.9)50,099 (6.7)
    Asian or Pacific Islander3,922 (1.8)12,351 (1.6)
    Native American605 (0.3)2,020 (0.3)
    other3,132 (1.0)11,518 (1.5)
    missing53,868 (25.1)188,118 (25.1)
Charlson comorbidity index, mean (SD)2.79 (2.18)2.84 (2.21)<0.001
Procedures, n (%)
    mechanical ventilation38,231 (17.8)114,902 (15.3)<0.001
    dialysis18,071 (8.4)66,572 (8.9)<0.001
Primary diagnosis, n (%)a
    AKI45,203 (21.0)169,759 (22.7)<0.001
    sepsis45,409 (21.0)137,713 (18.4)<0.001
    pneumonia35,882 (16.7)107,761 (14.4)<0.001
    acute myocardial infarction24,879 (11.6)74,466 (9.9)<0.001
    heart failure30,358 (14.1)113,900 (15.2)0.007
    gastrointestinal bleed8,533 (4.0)26,415 (3.5)<0.001
    pancreatitis4,411 (2.1)13,065 (1.7)<0.001
    liver failure3,825 (1.8)11,769 (1.6)<0.001
    other16,332 (7.6)94,050 (12.6)<0.001
Hospital size, n (%)<0.001
    small23,553 (11.0)82,754 (11.1)
    medium53,887 (25.1)182,942 (24.4)
    large137,392 (63.9)483,202 (64.5)
Hospital teaching status, n (%)<0.001
    nonteaching118,251 (55.0)405,588 (54.2)
    teaching96,581 (45.0)343,310 (45.8)
  • aFor admissions where AKI was not the primary diagnosis, AKI was present as a secondary (co-existing) diagnosis.