No AKI (n = 146 030)	AKI (n = 62 553)	CA-⁠AKI (n = 52 048)	HA-⁠AKI (n = 10 505)
Age (y), mean ± SD	58.9 ± 18.6	69.3 ± 14.8	69.8 ± 14.9	67.1 ± 14.2
Age group (y), n (%)
18-39	25 839 (17.7)	2425 (3.9)	2001 (3.8)	424 (4.0)
40-59	45 583 (31.2)	12 329 (19.7)	9888 (19.0)	2441 (23.2)
60-74	41 982 (28.7)	22 992 (36.8)	18 716 (36.0)	4276 (40.7)
≥75	626 (22.3)	807 (39.7)	443 (41.2)	3364 (32.0)
Gender, n (%)
Male	69 252 (47.4)	37 252 (59.6)	30 863 (59.3)	6389 (60.8)
Race/ethnicity, n (%)
Non-⁠Hispanic White	67 067 (45.9)	27 862 (44.5)	23 420 (45.0)	4442 (42.3)
Non-Hispanic Black	25 549 (17.5)	16 873 (27.0)	14 698 (28.2)	2175 (20.7)
Hispanic	34 084 (23.3)	9637 (15.4)	7366 (14.2)	2271 (21.6)
Other or unknown	19 330 (13.2)	8181 (13.1)	6564 (12.6)	1617 (15.4)
Primary payer, n (%)
Medicare	60 690 (41.6)	40 599 (64.9)	34 491 (66.3)	6108 (58.1)
Medicaid	26 471 (18.1)	6951 (11.1)	5503 (10.6)	1448 (13.8)
Private insurance	42 837 (29.3)	11 031 (17.6)	8785 (16.9)	2246 (21.4)
Uninsured	6926 (4.7)	1462 (2.3)	1175 (2.3)	287 (2.7)
Other/unknown	9106 (6.2)	2510 (4.0)	2094 (4.0)	416 (4.0)
Hospital size, n (%)
1-299	54 233 (37.1)	22 013 (35.2)	18 700 (35.9)	3313 (31.5)
300-499	43 288 (29.6)	19 137 (30.6)	16 028 (30.8)	3109 (29.6)
≥500	48 368 (33.1)	21 355 (34.1)	17 288 (33.2)	4067 (38.7)
Population served, n (%)
Rural	17 479 (12.0)	6542 (10.5)	5597 (10.8)	945 (9.0)
Urban	128 551 (88.0)	56 011 (89.5)	46 451 (89.2)	9560 (91.0)
Teaching status, n (%)
Non-teaching	77 636 (53.2)	30 297 (48.4)	25 416 (48.8)	4881 (46.5)
Teaching	68 394 (46.8)	32 256 (51.6)	26 632 (51.2)	5624 (53.5)
Region of hospital, n (%)
Midwest	27 057 (18.5)	12 162 (19.4)	10 445 (20.1)	1717 (16.3)
Northeast	28 703 (19.7)	15 665 (25.0)	12 721 (24.4)	2944 (28.0)
South	70 875 (48.5)	28 130 (45.0)	23 663 (45.5)	4467 (42.5)
West	19 395 (13.3)	6596 (10.5)	5219 (10.0)	1377 (13.1)
Admission type, n (%)
Elective	6933 (4.7)	1092 (1.7)	917 (1.8)	175 (1.7)
Emergency	118 975 (81.5)	54 207 (86.7)	45 214 (86.9)	8993 (85.6)
Urgent	18 747 (12.8)	6884 (11.0)	5614 (10.8)	1270 (12.1)
Trauma center	487 (0.3)	158 (0.3)	136 (0.3)	22 (0.2)
Unknown	888 (0.6)	212 (0.3)	167 (0.3)	45 (0.4)
Admission point of origin, n (%)
Non-healthcare facility (eg, home)	119 463 (81.8)	48 729 (77.9)	40 395 (77.6)	8334 (79.3)
Clinic	7698 (5.3)	2907 (4.6)	2505 (4.8)	402 (3.8)
Transfer from acute care facility	13 346 (9.1)	6734 (10.8)	5424 (10.4)	1310 (12.5)
Transfer from long-term care facility	4389 (3.0)	3737 (6.0)	3347 (6.4)	390 (3.7)
Other/unknown	1134 (0.8)	446 (0.7)	377 (0.7)	69 (0.7)
MS-DRG categorization, n (%)
Medical	138 390 (94.8)	58 530 (93.6)	49 586 (95.3)	8944 (85.1)
Surgical	7597 (5.2)	4013 (6.4)	2457 (4.7)	1556 (14.8)
History of comorbidities, n (%)
Charlson Comorbidity Index	1.5 ± 1.9	3.0 ± 2.4	3.1 ± 2.4	2.7 ± 2.4
Charlson comorbidities
Chronic kidney disease	12 413 (8.5)	26 334 (42.1)	23 249 (44.7)	3085 (29.4)
Hypertension	85 584 (58.6)	52 341 (83.7)	43 884 (84.3)	8457 (80.5)
Diabetes	50 941 (34.9)	33 320 (53.3)	27 710 (53.2)	5610 (53.4)
Anemia	26 886 (18.4)	23 166 (37.0)	18 688 (35.9)	4478 (42.6)
In-hospital complications
Dehydration present on admission	11 822 (8.1)	14 982 (24.0)	13 929 (26.8)	1053 (10.0)
Sepsis	30 182 (20.7)	29 559 (47.3)	22 593 (43.4)	6966 (66.3)
Acute respiratory failure	73 521 (50.3)	36 895 (59.0)	30 664 (58.9)	6231 (59.3)
Discharge status
Home	91 148 (62.4)	16 927 (27.1)	15 758 (30.3)	1169 (11.1)
Home health	16 398 (11.2)	6997 (11.2)	6120 (11.8)	877 (8.3)
Nursing or rehabilitation facility	19 421 (13.3)	13 222 (21.1)	11 189 (21.5)	2033 (19.4)
Transferred to an acute care hospital	696 (0.5)	262 (0.4)	229 (0.4)	33 (0.3)
Hospice	3141 (2.2)	3175 (5.1)	2801 (5.4)	374 (3.6)
Expired	8730 (6.0)	19 388 (31.0)	13 721 (26.4)	5667 (53.9)
Other/unknown	6496 (4.4)	2582 (4.1)	2230 (4.3)	352 (3.4)