Table 2.
Results from the subanalyses.
| Number of (sub)studies | Effect size* | I2 | p-value | Interaction p-value | ||
|---|---|---|---|---|---|---|
| In-hospital mortality—effect of AKI on outcome | ||||||
| AKI definition | AKIN | 13 | 10.00 (5.08; 19.69) | 61% | 0.002 | 0.237 |
| KDIGO | 14 | 4.60 (2.28; 9.29) | 47% | 0.049 | ||
| pRIFLE | 19 | 7.49 (4.36; 12.86) | 71% | <0.001 | ||
| Age group | Neonates | 7 | 3.75 (1.80; 7.84) | 0% | 0.493 | 0.004 |
| Infants | 11 | 4.08 (2.13; 7.84) | 15% | 0.304 | ||
| Toddlers | 20 | 9.29 (5.37; 16.10) | 79% | <0.001 | ||
| Children | 11 | 11.80 (6.62; 21.02) | 0% | 0.628 | ||
| Study design | Retrospective | 40 | 7.48 (5.29; 10.58) | 57% | <0.001 | 0.493 |
| Prospective | 9 | 5.65 (2.28; 14.02) | 44% | 0.098 | ||
| Number of centers | Single center | 44 | 6.96 (4.93; 9.82) | 66% | <0.001 | 0.414 |
| Multicenter | 5 | 9.37 (3.83; 22.96) | 0% | 0.624 | ||
| Era | 2001–2010 | 28 | 8.22 (5.66; 11.92) | 55% | <0.001 | 0.218 |
| 2011–2020 | 20 | 6.32 (3.29; 12.12) | 60% | <0.001 | ||
| In-hospital mortality—proportion analysis within AKI patients | ||||||
| AKI definition | AKIN | 13 | 13.7% (8.4–21.6%) | 82.7% | <0.001 | 0.089 |
| KDIGO | 14 | 4.9% (2.4–9.6%) | 60.7% | 0.002 | ||
| pRIFLE | 19 | 7.9% (4.8–12.8%) | 94.4% | <0.001 | ||
| Age group | Neonates | 7 | 10.5% (7.0–15.3%) | 48.5% | 0.076 | 0.447 |
| Infants | 11 | 5.8% (2.8–11.7%) | 79.1% | <0.001 | ||
| Toddlers | 20 | 10.3% (6.8–15.3%) | 94.0% | <0.001 | ||
| Children | 11 | 7.2% (2.9–16.6%) | 81.2% | <0.001 | ||
| Study design | Retrospective | 40 | 9.1% (6.5–12.6%) | 90.8% | <0.001 | 0.360 |
| Prospective | 9 | 6.4% (3.2–12.3%) | 74.3% | <0.001 | ||
| Number of centers | Single center | 44 | 8.9% (6.3–12.3%) | 89.4% | <0.001 | 0.080 |
| Multicenter | 5 | 6.1% (4.7–7.8%) | 0% | 0.587 | ||
| Era | 2001–2010 | 28 | 8.5% (5.5–12.9%) | 93.2% | <0.001 | 0.456 |
| 2011–2020 | 20 | 8.3% (5.4–12.3%) | 65.7% | 0.001 | ||
| Need for RRT—effect of AKI on outcome | ||||||
| AKI definition | AKIN | 13 | 33.91 (13.55; 84.88) | 81% | <0.001 | 0.256 |
| KDIGO | 10 | 26.63 (4.21; 168.55) | 64% | 0.011 | ||
| pRIFLE | 23 | 13.17 (6.53; 26.56) | 61% | <0.001 | ||
| Age group | Neonates | 5 | 11.61 (2.31; 58.43) | 59% | 0.047 | 0.494 |
| Infants | 9 | 14.28 (4.56; 44.77) | 54% | 0.032 | ||
| Toddlers | 18 | 29.84 (10.87; 81.93) | 74% | <0.001 | ||
| Children | 17 | 13.20 (6.42; 27.17) | 12% | 0.320 | ||
| Study design | Retrospective | 38 | 22.31 (12.50; 39.82) | 77% | <0.001 | 0.035 |
| Prospective | 11 | 8.64 (3.92; 19.03) | 0% | 0.590 | ||
| Number of centers | Single center | 43 | 18.54 (10.69; 32.18) | 74% | <0.001 | 0.659 |
| Multicenter | 6 | 18.84 (11.65; 30.47) | 0% | 0.897 | ||
| Era | 2001–2010 | 30 | 21.86 (10.45; 45.75) | 80% | <0.001 | 0.277 |
| 2011–2020 | 19 | 13.43 (7.58; 23.77) | 4% | <0.001 | ||
| Need for RRT—proportion analysis within AKI patients | ||||||
| AKI definition | AKIN | 13 | 13.0% (6.0–26.2%) | 95.7% | <0.001 | 0.166 |
| KDIGO | 10 | 5.4% (2.0–14.1%) | 79.0% | <0.001 | ||
| pRIFLE | 23 | 8.0% (4.6–13.8%) | 91.1% | <0.001 | ||
| Age group | Neonates | 5 | 26.2% (11.0–50.5%) | 96.7% | <0.001 | 0.050 |
| Infants | 9 | 8.0% (3.3–18.0%) | 89.0% | <0.001 | ||
| Toddlers | 18 | 8.2% (4.7–14.1%) | 94.5% | <0.001 | ||
| Children | 17 | 5.1% (2.2–11.2%) | 63.1% | 0.012 | ||
| Study design | Retrospective | 38 | 8.7% (5.4–13.8%) | 93.5% | <0.001 | 0.359 |
| Prospective | 11 | 6.2% (3.6–10.6%) | 62.4% | 0.014 | ||
| Number of centers | Single center | 43 | 8.1% (5.1–12.7%) | 92.5% | <0.001 | 0.548 |
| Multicenter | 6 | 6.5% (3.6–11.5%) | 86.1% | <0.001 | ||
| Era | 2001–2010 | 30 | 7.1% (3.8–12.9%) | 94.3% | <0.001 | 0.507 |
| 2011–2020 | 19 | 9.2% (5.9–13.9%) | 84.0% | <0.001 | ||
| Cardiac arrhythmias—effect of AKI on outcome | ||||||
| AKI definition | AKIN | 3 | 3.51 (0.57; 21.53) | 46% | 0.159 | 0.149 |
| KDIGO | 4 | 1.69 (0.99; 2.87) | 39% | 0.457 | ||
| pRIFLE | 2 | 3.61 (0.28; 46.25) | 0% | 0.415 | ||
| Age group | Neonates | 2 | 2.39 (0.00; 1822.33) | 52% | 0.150 | <0.001 |
| Infants | 3 | 1.65 (1.01; 2.69) | 0% | 0.672 | ||
| Toddlers | 2 | 3.16 (1.54; 6.50) | 0% | 0.749 | ||
| Children | 3 | 5.49 (1.60; 18.88) | 0% | 0.581 | ||
| Study design | Retrospective | 10 | 2.67 (1.86–4.80) | 40% | 0.091 | N/A |
| Prospective | 0 | N/A | N/A | N/A | ||
| Number of centers | Single center | 10 | 2.67 (1.86–4.80) | 40% | 0.091 | N/A |
| Multicenter | 0 | N/A | N/A | N/A | ||
| Era | 2001–2010 | 7 | 3.01 (2.01; 4.51) | 11% | 0.344 | 0.286 |
| 2011–2020 | 3 | 2.11 (0.60; 7.38) | 43% | 0.172 | ||
| Cardiac arrhythmias—proportion analysis within AKI patients | ||||||
| AKI definition | AKIN | 3 | 25.8% (16.7–37.7%) | 75.7% | 0.032 | 0.724 |
| KDIGO | 4 | 32.0% (19.3–48.0%) | 71.4% | 0.024 | ||
| pRIFLE | 2 | 28.3% (18.0–41.6%) | 83.5% | 0.021 | ||
| Age group | Neonates | 2 | 42.6% (30.9–55.2%) | 74.9% | 0.031 | 0.017 |
| Infants | 3 | 22.7% (16.6–30.1%) | 0% | 0.583 | ||
| Toddlers | 2 | 35.3% (29.0–42.2%) | 0% | 0.632 | ||
| Children | 3 | 27.6% (15.1–45.0%) | 74.9% | 0.014 | ||
| Study design | Retrospective | 10 | 29.0% (23.1–35.7%) | 66.6% | 0.091 | N/A |
| Prospective | 0 | N/A | N/A | N/A | ||
| Number of centers | Single center | 10 | 29.0% (23.1–35.7%) | 66.6% | 0.091 | N/A |
| Multicenter | 0 | N/A | N/A | N/A | ||
| Era | 2001–2010 | 7 | 29.7% (22.3–38.2%) | 69.8% | 0.051 | 0.781 |
| 2011–2020 | 3 | 27.8% (18.8–39.1%) | 71.5% | 0.034 | ||
| Ventilation (days) | ||||||
| AKI definition | AKIN | 8 | 1.95 (0.00; 3.91) | 99% | <0.001 | 0.125 |
| KDIGO | 11 | 0.97 (0.03; 1.90) | 99% | <0.001 | ||
| pRIFLE | 15 | 2.39 (1.12; 3.67) | 99% | <0.001 | ||
| Age group | Neonates | 6 | 1.76 (0.17; 3.35) | 97% | <0.001 | 0.230 |
| Infants | 6 | 1.47 (−0.35; 3.29) | 99% | <0.001 | ||
| Toddlers | 14 | 2.50 (0.90; 4.10) | 99% | <0.001 | ||
| Children | 8 | 0.98 (0.26; 1.71) | 99% | <0.001 | ||
| Study design | Retrospective | 25 | 1.98 (1.09; 2.86) | 99% | <0.001 | 0.351 |
| Prospective | 9 | 1.27 (−0.19; 2.72) | 99% | <0.001 | ||
| Number of centers | Single center | 33 | 1.70 (0.99; 2.41) | 99% | <0.001 | 0.002 |
| Multicenter | 1 | 4.78 (2.96; 6.60) | N/A | N/A | ||
| Era | 2001–2010 | 16 | 1.68 (0.72; 2.65) | 99% | <0.001 | 0.795 |
| 2011–2020 | 18 | 1.87 (0.72; 3.02) | 98% | <0.001 | ||
| PICU length of stay (days) | ||||||
| AKI definition | AKIN | 9 | 2.78 (2.20; 3.36) | 96% | <0.001 | 0.156 |
| KDIGO | 11 | 2.62 (1.46; 3.77) | 95% | <0.001 | ||
| pRIFLE | 14 | 4.11 (2.14; 6.07) | 98% | <0.001 | ||
| Age group | Neonates | 5 | 3.57 (2.68; 4.46) | 93% | <0.001 | 0.029 |
| Infants | 8 | 2.11 (0.69; 3.52) | 96% | <0.001 | ||
| Toddlers | 13 | 4.69 (2.63; 6.74) | 98% | <0.001 | ||
| Children | 12 | 2.61 (1.67; 3.55) | 94% | <0.001 | ||
| Study design | Retrospective | 16 | 3.45 (2.39; 4.50) | 97% | <0.001 | 0.525 |
| Prospective | 12 | 2.97 (1.76; 4.18) | 97% | <0.001 | ||
| Number of centers | Single center | 33 | 3.34 (2.44; 4.25) | 97% | <0.001 | 0.953 |
| Multicenter | 5 | 3.29 (1.06; 5.52) | 97% | <0.001 | ||
| Era | 2001–2010 | 22 | 3.16 (2.11; 4.21) | 98% | <0.001 | 0.225 |
| 2011–2020 | 15 | 3.27 (2.14; 4.41) | 96% | <0.001 | ||
| Hospital length of stay (days) | ||||||
| AKI definition | AKIN | 9 | 5.27 (3.00; 7.54) | 97% | <0.001 | 0.081 |
| KDIGO | 12 | 2.87 (0.73; 5.00) | 98% | <0.001 | ||
| pRIFLE | 11 | 7.91 (3.15; 12.67) | 97% | <0.001 | ||
| Age group | Neonates | 6 | 4.73 (−2.52; 11.99) | 97% | <0.001 | 0.516 |
| Infants | 9 | 3.56 (0.52; 6.60) | 98% | <0.001 | ||
| Toddlers | 10 | 7.47 (2.32; 12.63) | 98% | <0.001 | ||
| Children | 11 | 4.94 (2.65; 7.23) | 98% | <0.001 | ||
| Study design | Retrospective | 27 | 4.51 (2.44; 6.68) | 98% | <0.001 | 0.255 |
| Prospective | 9 | 6.49 (3.23; 9.75) | 98% | <0.001 | ||
| Number of centers | Single center | 31 | 4.72 (2.83; 6.61) | 98% | <0.001 | 0.325 |
| Multicenter | 5 | 6.28 (2.70; 9.86) | 96% | <0.001 | ||
| Era | 2001–2010 | 23 | 4.20 (2.35; 6.04) | 99% | <0.001 | 0.135 |
| 2011–2020 | 13 | 7.12 (3.32; 10.92) | 96% | <0.001 | ||
AKI, acute kindey injury; AKIN, Acute Kidney Injury Network; KDIGO, Kidney Disease Improving Global Outcomes; PICU, pediatric intensive care unit; pRIFLE, pediatric RIFLE; R, randomized; RIFLE, Risk for renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function and End-stage renal disease; RRT, renal replacement therapy. Significant p-values (p <0.05) are indicated in bold.