Table 1. Baseline Characteristics by AKI Recovery Patterns.
| Variable | Overall (N = 1538) | No AKI (n = 769) | Resolving AKI (n = 475) | Nonresolving AKI (n = 294) | P valuea |
|---|---|---|---|---|---|
| Patients at center, No. (%) | |||||
| Yale | 308 (20) | 154 (20) | 75 (16) | 79 (27) | .001 |
| Vanderbilt | 502 (33) | 251 (33) | 151 (32) | 100 (34) | |
| Kaiser Permanente | 312 (20) | 156 (20) | 96 (20) | 60 (20) | |
| University of Washington | 416 (27) | 208 (27) | 153 (32) | 55 (19) | |
| Age, mean (SD), y | 64.6 (12.7) | 65.4 (12.6) | 63.2 (12.7) | 64.5 (12.8) | .15 |
| Male sex, No. (%) | 964 (63) | 445 (58) | 313 (66) | 206 (70) | .24 |
| Black race, No. (%) | 204 (13) | 81 (11) | 79 (17) | 44 (15) | .61 |
| BMI, mean (SD) | 31.0 (7.7) | 30.5 (7.0) | 31.2 (8.1) | 32.1 (8.7) | .16 |
| Types 1 and 2 diabetes, No. (%) | 658 (43) | 271 (35) | 231 (49) | 156 (53) | .24 |
| Chronic kidney disease, No. (%) | 612 (40) | 306 (40) | 186 (39) | 120 (41) | .65 |
| History of proteinuria, No. (%) | 111 (7) | 35 (5) | 42 (9) | 34 (12) | .40 |
| Congestive heart failure, No. (%) | 327 (21) | 122 (16) | 120 (25) | 85 (29) | .28 |
| Sepsis, No. (%) | 144 (9) | 26 (3) | 86 (18) | 32 (11) | .007 |
| Use of vasopressors, No. (%) | 485 (32) | 215 (28) | 142 (30) | 128 (44) | <.001 |
| Intravenous contrast administered, No. (%) | 349 (23) | 183 (24) | 110 (23) | 56 (19) | .21 |
| Major surgical procedure, No. (%) | 698 (45) | 385 (50) | 165 (35) | 148 (50) | <.001 |
| Shock, No. (%) | 114 (7) | 26 (3) | 66 (14) | 22 (7) | .007 |
| Acute heart failure, No. (%) | 76 (5) | 17 (2) | 34 (7) | 25 (9) | .49 |
| Mechanical ventilation, No. (%) | 66 (4) | 12 (2) | 18 (4) | 36 (12) | <.001 |
| Acute myocardial infarction, No. (%) | 51 (3) | 21 (3) | 20 (4) | 10 (3) | .70 |
| Baseline outpatient serum creatinine concentration, mean (SD), mg/dL | 1.2 (0.5) | 1.1 (0.4) | 1.2 (0.5) | 1.3 (0.6) | .37 |
| Baseline outpatient eGFR, mean (SD), mL/min/1.73 m2 | 68.7 (25.0) | 70.2 (24.1) | 67.8 (25.7) | 66.2 (26.0) | .42 |
| Maximum serum creatinine concentration within 72 h of AKI diagnosis, mean (SD), mg/dL | 1.7 (1.3) | 1.1 (0.4) | 2.4 (1.5) | 2.4 (1.8) | .86 |
| Serum creatinine concentration at hospital discharge, mean (SD), mg/dL | 1.2 (0.8) | 1.0 (0.4) | 1.3 (0.7) | 1.7 (1.2) | <.001 |
| Maximum KDIGO stage of AKI within 72 h after AKI diagnosis, No. (%) | |||||
| 0 | 769 (50) | 769 (100) | 0 | 0 | .05 |
| 1 | 566 (37) | 0 | 336 (71) | 230 (78) | NA |
| 2 | 123 (8) | 0 | 87 (18) | 36 (12) | NA |
| 3 | 80 (5) | 0 | 52 (11) | 28 (10) | NA |
| Length of hospital stay, median (IQR), d | 5 (3-8) | 4 (3-7) | 6 (3-8) | 8 (5-13) | <.001 |
Abbreviations: AKI, acute kidney injury; BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); eGFR, estimated glomerular filtration rate; IQR, interquartile range; KDIGO, Kidney Disease: Improving Global Outcomes; NA, not applicable.
SI conversion factor: To convert to creatinine to micromoles per liter, multiply by 88.4.
a
Comparing the outcome of AKI recovery between patients with resolving AKI and patients with nonresolving AKI.