Table 1.
Characteristics of included patients before admission and during hospitalization in the overall cohort and according to degree of follow-up within 30-days
| Characteristic | Overalla (N = 627) | Both SCr and Visit within 30-daysa (N = 434) | Only SCr within 30-daysa (N = 64) | Only Visit within 30-daysa (N = 81) | Neither SCr nor visit within 30-daysa (N = 48) |
|---|---|---|---|---|---|
| Age, y | 68 ± 18 | 69 ± 18 | 70 ± 18 | 70 ± 18 | 61 ± 20 |
| Male Sex | 291 (46) | 208 (48) | 33 (52) | 31 (38) | 19 (40) |
| Non-Hispanic Caucasian | 556 (89) | 385 (89) | 56 (88) | 76 (94) | 39 (81) |
| Education levelb | |||||
| 8th grade or less | 58 (10) | 47 (11) | 3 (5) | 3 (4) | 5 (12) |
| Some or completed high-school or GED | 76 (13) | 53 (13) | 8 (13) | 8 (10) | 7 (17) |
| Some or completed college | 219 (36) | 160 (38) | 16 (26) | 29 (37) | 14 (34) |
| Post-graduate studies | 252 (42) | 163 (39) | 35 (57) | 39 (49) | 15 (37) |
| HOUSES z-scorec | −1.2 ± 3.0 | −1.3 ± 2.9 | −1.5 ± 3.5 | −1.2 ± 2.9 | −0.6 ± 3.7 |
| Body mass index, kg/m2 | 29 ± 9 | 29 ± 9 | 30 ± 9 | 28 ± 7 | 27 ± 9 |
| Pre-admission SCr, mg/dLd | 1.2 ± 1.1 | 1.3 ± 1.3 | 1.2 ± 0.7 | 1.0 ± 0.3 | 1.0 ± 0.3 |
| Pre-admission eGFR, mL/min/1.73 m2 | 63 ± 24 | 62 ± 24 | 63 ± 19 | 68 ± 24 | 71 ± 26 |
| eGFR < 60mL/min/1.73 m2 | 335 (53) | 231 (53) | 37 (58) | 43 (53) | 24 (50) |
| Comorbidity burden based on CCI | 5.2 ± 3.8 | 5.4 ± 3.7 | 5.1 ± 3.7 | 5.1 ± 4.2 | 3.8 ± 3.4 |
| Cardiovascular disease | 366 (58) | 263 (61) | 31 (48) | 51 (63) | 21 (44) |
| Heart failure | 288 (46) | 205 (47) | 34 (53) | 34 (42) | 15 (31) |
| Peripheral vascular disease | 342 (55) | 246 (57) | 34 (53) | 41 (51) | 21 (44) |
| CKD | 379 (61) | 278 (64) | 36 (56) | 42 (52) | 23 (48) |
| Diabetes | 271 (43) | 192 (44) | 33 (52) | 28 (35) | 18 (38) |
| ICU during hospitalization | 269 (43) | 189 (44) | 28 (44) | 36 (44) | 16 (33) |
| Maximum AKI severity | |||||
| Stage 2 | 400 (64) | 249 (57) | 41 (64) | 71 (88) | 39 (81) |
| Stage 3 | 227 (36) | 185 (43) | 23 (36) | 10 (12) | 9 (19) |
| Dialysis during hospitalization | 26 (4) | 20 (5) | 4 (6) | 1 (1) | 1 (2) |
| Discharge SCr, mg/dL | 1.9 ± 1.2 | 2.0 ± 1.3 | 1.8 ± 1.1 | 1.3 ± 0.6 | 1.5 ± 0.8 |
| AKI recovery by discharge | |||||
| Stage 0 (SCr 1–1.5x) | 333 (53) e | 215 (50) | 34 (53) | 56 (69) | 28 (58) |
| Stage 1 (SCr 1.5–1.9x) | 120 (19) | 86 (20) | 12 (19) | 14 (17) | 8 (17) |
| Stage 2 (SCr 2–2.9x) | 118 (19) | 84 (19) | 12 (19) | 11 (14) | 11 (23) |
| Stage 3 (SCr >3x or >4 mg/dL) | 56 (9) | 49 (11) | 6 (9) | 0 (0) | 1 (2) |
| Discharge eGFR, mL/min/1.73 m2 | 46 ± 28 | 42 ± 26 | 47 ± 29 | 59 ± 28 | 57 ± 31 |
| Hospital length of stay, days | 9.0 ± 12.1 | 9.5 ± 13.6 | 6.9 ± 6.0 | 8.9 ± 9.7 | 7.2 ± 7.1 |
| Discharge Disposition | |||||
| Home/Self-Care | 351 (56) | 242 (56) | 29 (45) | 44 (54) | 36 (75) |
| Acute Care Hospital | 3 (0.5) | 1 (0.2) | 1 (1.6) | 0 (0.0) | 1 (2.1) |
| SNF/Long Term Care Facility | 186 (30) | 127 (29) | 26 (41) | 26 (32) | 7 (15) |
| Left against medical advice/ discontinued care | 2 (0.3) | 1 (0.2) | 1 (1.6) | 0 (0.0) | 0 (0.0) |
| Home with Home Health Care services | 65 (10) | 50 (12) | 3 (5) | 10 (12) | 2 (4) |
| Rehab facility | 13 (2) | 10 (2) | 2 (3) | 1 (1) | 0 (0) |
| Inpatient Psychiatry | 7 (1) | 3 (0.7) | 2 (3) | 0 (0) | 2 (4) |
AKI: Acute kidney injury; CCI: Charlson Comorbidity Index; eGFR: Estimated glomerular filtration rate; ICU: Intensive care unit; SCr: Serum creatinine; SNF: Skilled nursing facility
Reported as count (percent) for categorical variables and mean ± standard deviation for continuous variables
Data available for 605 of the overall cohort, 423 in the both SCr and visit group, 62 in the only SCr group, 79 in the only visit group, and 41 in the neither SCr nor visit group
The HOUSES index is an individual-level socioeconomic status measure that includes four items of publically available property data based on someone's address (number of bedrooms, number of bathrooms, square footage of the unit, & estimated building value of the unit).[26] Results of the four items are aggregated and standardized into an overall Z-score for the individual. Higher Z-scores reflect a higher socioeconomic status.
Preadmission serum creatinine was available for 416 individuals in the overall cohort, 297 in the both SCr and visit group, 45 in the only SCr group, 47 in the only visit group, and 27 in the neither SCr nor visit group. For the remainder of individuals the baseline serum creatinine was estimated.
Of the patients with Stage 0 AKI recovery, 158 (47%) individuals returned to baseline or better kidney function whereas 175 (53%) individuals had a SCr between >1- and <1.5-times baseline.