Table 1.
Sociodemographic and clinical features of AKI episodes by peak stage AKI and for all episodes of AKI.
| Variables | AKI stage 2 | AKI stage 3 | All AKI (AKI stage 2 and 3) |
|---|---|---|---|
| Total N (%) | 498 (50.3) | 491 (49.6) | 989 (100.0) |
| Age group (years) N (%) | |||
| 18–29 | 10 (2.0) | 7 (1.4) | 17 (1.7) |
| 30–49 | 31 (6.2) | 46 (9.4) | 77 (7.8) |
| 50–64 | 72 (14.5) | 96 (19.6) | 168 (16.9) |
| 65–74 | 109 (21.9) | 99 (20.2) | 208 (21.0) |
| 75–84 | 157 (31.5) | 141 (28.7) | 298 (30.1) |
| ≥85 | 119 (23.9) | 102 (20.8) | 221 (22.3) |
| Sex N (%) | |||
| Female | 245 (49.2) | 209 (42.6) | 454 (45.9) |
| Male | 253 (50.8) | 282 (57.4) | 535 (54.1) |
| Index of Multiple Deprivation quintile N (%) – missing N=2 | |||
| Deprivation score-1 | 101 (20.3) | 85 (17.3) | 186 (18.8) |
| Deprivation score-2 | 115 (23.1) | 102 (20.8) | 217 (22.0) |
| Deprivation score-3 | 98 (19.7) | 104 (21.2) | 202 (20.5) |
| Deprivation score-4 | 99 (19.9) | 89 (18.2) | 188 (19.1) |
| Deprivation score-5 | 84 (16.9) | 110 (22.4) | 194 (19.7) |
| Ethnicity N (%) – missing N=72 | |||
| Asian | 18 (3.8) | 14 (3.1) | 32 (3.5) |
| Black | 16 (3.4) | 20 (4.5) | 36 (3.9) |
| Other/Mixed | 11 (2.4) | 11 (2.4) | 22 (2.4) |
| White | 423 (90.4) | 404 (90.0) | 827 (90.2) |
| Type of admission N (%) from HES England only (n=950) | |||
| Elective | 40 (8.3) | 28 (6) | 68 (7.2) |
| Emergency | 443 (91.7) | 439 (94.0) | 882 (92.8) |
| Type-AKI N (%) from AKI MPI + HES England only (n=950) | |||
| Community acquired AKI | 334 (69.2) | 351 (75.2) | 685 (72.1) |
| Hospital acquired AKI | 149 (30.8) | 116 (24.8) | 265 (27.9) |
| Cause of AKI N (%) | |||
| Hypovolaemia | 151 (30.3) | 115 (23.4) | 266 (26.9) |
| Circulatory failure | 51 (10.2) | 59 (12.0) | 110 (11.1) |
| Sepsis | 166 (33.3) | 149 (30.3) | 315 (31.8) |
| Rhabdomyolysis | 3 (0.6) | 2 (0.4) | 5 (0.5) |
| Medication induced | 16 (3.2) | 24 (4.9) | 40 (4.0) |
| Obstruction | 32 (6.4) | 68 (13.8) | 100 (10.1) |
| Multifactorial | 17 (3.4) | 34 (6.9) | 51 (5.1) |
| No specific cause | 56 (11.2) | 36 (7.3) | 92 (9.3) |
| Not completed | 6 (1.2) | 4 (0.8) | 10 (1.0) |
| Admitting specialty N (%) | |||
| Medicine | 350 (70.3) | 364 (74.1) | 714 (72.1) |
| Surgery | 109 (21.9) | 86 (17.5) | 195 (19.7) |
| Intensive treatment unit | 24 (4.8) | 30 (6.1) | 54 (5.4) |
| Discharged from emergency department | 3 (0.6) | 1 (0.2) | 4 (0.4) |
| Other | 11 (2.2) | 10 (2.0) | 2 (21.0) |
| Not completed | 1 (0.2) | 0 (0.0) | 1 (0.1) |
| Serum creatinine re-checked within 30 days N (%) if alive 30 days post discharge (AKI stage 2 N=330, AKI stage 3 N=298, All AKI N=628) | 221 (67.0) | 224 (75.2) | 445 (70.9) |
| Complications of AKI N (%) (missing N=17) | |||
| Hyperkalaemia | 59 (11.9) | 130 (26.5) | 189 (19.2) |
| Uraemia | 61 (12.2) | 114 (23.3) | 175 (17.7 |
| Pulmonary oedema | 51 (10.3) | 52 (10.6) | 103 (10.5) |
| Acidosis | 134 (27.2) | 204 (41.8) | 338 (34.5) |
| Median length of stay (days) (IQR) | 10(5–19) | 11(5–20) | 10(5–20) |
| Readmission within 90 days N (%) if alive 90 days post discharge (AKI stage 2 N=304, AKI stage 3 N=283, All AKI N=587) | 99 (32.6) | 115 (40.6) | 214 (36.5) |
| Renal function returned to baseline N (%) | 286 (57.4) | 209 (42.6) | 495 (50.1) |
| In hospital mortality N (%) | 141 (28.3) | 166 (33.8) | 307 (31.0) |
| 30-day mortality N (%) | 153 (30.7) | 174 (35.4) | 327 (33.1) |
| 90-day mortality N (%) | 186 (37.3) | 202 (41.1) | 388 (39.2) |
| 1-year mortality N (%) | 236 (47.4) | 251 (51.1) | 487 (49.2) |