Table 1. Baseline characteristics of included studies.
| First author, year | Study type | Location of study | Total, n | With AKI, n | Mean age | % Males | Follow-up period | Definition of AKI |
| Angeli, 2014 | P | Spain | 510 | 98 | 55 | 64.9 | 90 days | AKIN |
| Bıyık, 2016 | RT | Turkey | 277 | 108 | 62.1 | 57.8 | 4 years | KDIGO criteria |
| Bucsics, 2015 | RT | Austria | 239 | 78 | 54.9 | 66.9 | n/a | AKIN |
| Chen, 2011 | RT | Taiwan | 2,375 | 636 | 60.73 | 69.1 | 58 months | eGFR <60 |
| Choi, 2014 | RT | Korea | 643 | 83 | 57.4 | 74.3 | AKIN | |
| Cholongitas, 2009 | P | UK | 312 | 128 | 49.3 | NA | 96 weeks | Serum creatinine ≥300 mmol/L |
| Cholongitas,2009b | RT | UK | 412 | 205 | 49.3 | 59.2 | 17 years | RIFLE |
| de Araujo, 2014 | RT | Brazil | 46 | 20 | 56.94 | 63 | 13months | AKIN |
| du Cheyron, 2005 | RT | France | 186 | 73 | 56.4 | 69 | 5 years | ADQI definition |
| Fagundes, 2013 | P | Spain | 375 | 177 | 61 | 62 | 25 months | AKIN |
| Hampel, 2001 | RT | New Mexico | 93 | 23 | 57.5 | NA | 7 years | ↑serum creatinine >1.0 mg/dl |
| Hseih, 2017 | RT | Taiwan | 117 | 46 | 61 | 72 | 6 weeks | ICA |
| Huelin, 2017 | P | Spain and Italy | 547 | 290 | 61 | 67 | 90 days | ICA |
| Hung, 2012 | RT | Taiwan | 2592 | 145 | 57.5 | 70.8 | 1 year | ICD-9-CM |
| Jaques, 2018 | P | Switzerland | 105 | 55 | 58.0 | 71.4 | 2 years | AKIN |
| Jindal, 2015 | RT | India | 241 | 55 | 46.12 | 85.47 | 33 months | Mild or moderate AKI with cut-off creatinine at 3 mg/dL |
| Maiwall, 2015 | P | India | 451 | 122 | 46 | 86 | 1 year | AKIN |
| Marciano, 2017 | RT | Argentina | 108 | 37 | 61.5 | 59.6 | 3 years | KDIGO |
| Nuthalapati, 2017 | RT | USA | 339 | 96 | 57.0 | 63 | 5 years | AKIN |
| Pan, 2016 | P | Taiwan | 242 | 152 | 58 | 75.7 | 2 years | AKIN and RIFLE |
| Piano, 2013 | P | Italy | 233 | 61 | 65.3 | 64.4 | NA | AKIN & conventional criteria |
| Prakash, 2011 | P | India | 404 | 99 | 48.5 | 79 | 16 months | AKIN |
| Scott, 2013 | P | UK | 162 | 110 | 56.8 | 65.4 | 18 months | AKIN |
| Shi, 2016 | RT | China | 1167 | 308 | NA | NA | 1 year | KDIGO |
| Tandon, 2016 | RT | Canada | 4733 | 1850 | 60.4 | 64.3 | 10 years | KDIGO |
| Tsien, 2013 | P | Canada | 90 | 49 | 55.8 | 71.1 | 2 years | n/a |
| Warner, 2011 | RT | USA | 152 | 107 | 53 | 76% | 2 years | AKIN |
| Wong, 2013 | P | USA | 337 | 166 | 55.91 | 56 | 30 days | ADQI definition |
| Wong, 2017 | P | Multiple centers in North America | 653 | 307 | 56.7 | 64 | 30 days | ICA |
| Zhou, 2017 | RT | China | 333 | 60 | 55.68 | 63.06 | 2 years | KDIGO |
| Summary | 18,474 | 5,648 | 56.8 | 66.9 | Median: 12 months | NA |
Abbreviations: ADQI, Acute Dialysis Quality Initiative; AKI, acute kidney injury; AKIN, AKI Network; ICA, International Club of Ascites; KDIGO, Kidney Disease Improving Global Outcomes; RIFLE, Risk Injury and Failure; P, prospective; RT, retrospective.