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
| Weekend | Weekday | P Value | |
|---|---|---|---|
| Number of admissions | 214,832 | 748,898 | |
| Age, mean (SD), years | 69.4 (16.8) | 69.2 (16.5) | <0.001 |
| Women, n (%) | 103,705 (48.3) | 357,701 (47.8) | <0.001 |
| Race, n (%) | <0.001 | ||
| white | 109,110 (50.8) | 387,325 (51.7) | |
| black | 29,272 (13.6) | 97,467 (13.0) | |
| Hispanic | 14,923 (6.9) | 50,099 (6.7) | |
| Asian or Pacific Islander | 3,922 (1.8) | 12,351 (1.6) | |
| Native American | 605 (0.3) | 2,020 (0.3) | |
| other | 3,132 (1.0) | 11,518 (1.5) | |
| missing | 53,868 (25.1) | 188,118 (25.1) | |
| Charlson comorbidity index, mean (SD) | 2.79 (2.18) | 2.84 (2.21) | <0.001 |
| Procedures, n (%) | |||
| mechanical ventilation | 38,231 (17.8) | 114,902 (15.3) | <0.001 |
| dialysis | 18,071 (8.4) | 66,572 (8.9) | <0.001 |
| Primary diagnosis, n (%)a | |||
| AKI | 45,203 (21.0) | 169,759 (22.7) | <0.001 |
| sepsis | 45,409 (21.0) | 137,713 (18.4) | <0.001 |
| pneumonia | 35,882 (16.7) | 107,761 (14.4) | <0.001 |
| acute myocardial infarction | 24,879 (11.6) | 74,466 (9.9) | <0.001 |
| heart failure | 30,358 (14.1) | 113,900 (15.2) | 0.007 |
| gastrointestinal bleed | 8,533 (4.0) | 26,415 (3.5) | <0.001 |
| pancreatitis | 4,411 (2.1) | 13,065 (1.7) | <0.001 |
| liver failure | 3,825 (1.8) | 11,769 (1.6) | <0.001 |
| other | 16,332 (7.6) | 94,050 (12.6) | <0.001 |
| Hospital size, n (%) | <0.001 | ||
| small | 23,553 (11.0) | 82,754 (11.1) | |
| medium | 53,887 (25.1) | 182,942 (24.4) | |
| large | 137,392 (63.9) | 483,202 (64.5) | |
| Hospital teaching status, n (%) | <0.001 | ||
| nonteaching | 118,251 (55.0) | 405,588 (54.2) | |
| teaching | 96,581 (45.0) | 343,310 (45.8) |
aFor admissions where AKI was not the primary diagnosis, AKI was present as a secondary (co-existing) diagnosis.