Table 3.
Outcome variables by obstruction duration
| Obstruction duration ≤7 days | Obstruction duration >7 days | Total (N=1607) | P value | |
| (group 1, n=913) | (group 2, n=694) | |||
| Acute pyelonephritis, n (%) | 24 (10.2) | 46 (29.3) | 235 (14.6) | <0.001 |
| Peak CRP (mg/L) | 3.3 (0.8–42.3) | 31.3 (1.7–145.0) | 5.9 (1.0–73.3) | <0.001 |
| Peak SCr during admission (mg/dL) | 1.0 (0.8–1.3) | 1.0 (0.8–1.3) | 1.0 (0.8–1.3) | 0.454 |
| Lowest eGFR during admission (mL/min/1.73 m2)* |
72.4 (56.1–89.6) | 71.9 (53.4–88.6) | 72.0 (55.1–89.0) | 0.307 |
| AKI, n (%) | ||||
| No AKI | 542 (59.4) | 436 (62.8) | 978 (60.9) | 0.491 |
| KDIGO stage I | 274 (30.0) | 192 (27.7) | 466 (29.0) | |
| KDIGO stage II | 62 (6.8) | 39 (5.6) | 101 (6.3) | |
| KDIGO stage III | 34 (3.7) | 27 (3.9) | 61 (3.8) | |
| GFR 30% reduction, n (%) | 100 (11.0) | 105 (15.1) | 205 (12.8) | 0.016 |
| GFR 50% reduction, n (%) | 24 (2.6) | 39 (5.6) | 63 (3.9) | 0.003 |
| Final SCr (mg/dL) | 0.9 (0.7–1.1) | 0.9 (0.7–1.1) | 0.9 (0.7–1.1) | 0.004 |
| Final eGFR (mL/min/1.73 m2)* | 87.0 (71.1–102.4) | 81.0 (64.0–100.5) | 84.4 (68.3–101.1) | 0.001 |
| ΔGFR/year | 2.5 (0.0–35.8) | 5.7 (0.0–162.8) | 4.0 (0.0–78.5) | 0.004 |
*eGFR was calculated using the Isotope Dilution Mass Spectrometry (IDMS) traceable Modification of Diet in Renal Disease (MDRD) study equation (mL/min/1.73 m2).
AKI, acute kidney injury;CRP, C reactive protein; eGFR, estimated glomerular filtration rate;GFR, glomerular filtration rate; KDIGO, Kidney Disease: Improving Global Outcomes; SCr, serum creatinine.