Table 2.

Pooled incidence rate of AKI according to the KDIGO-equivalent definition

SubgroupStudies (n)Patients (n)Patients with AKI (n)AKI Incidence Rate (%)95% Confidence IntervalTest for Heterogeneity
I2 IndexQ Test P Value
All1543,585,911573,42423.221.0 to 25.799.9<0.001
Age category
 Adults1303,571,691569,86121.619.3 to 24.199.9<0.001
 Children2414,220356333.726.9 to 41.398.3<0.001
Clinical setting
 Community acquired7548,39848978.31.6 to 33.099.9<0.001
 Critical care41888,604272,58031.728.6 to 35.099.9<0.001
 Cardiac surgery42164,33333,15724.320.4 to 28.899.7<0.001
 Trauma414,947255719.913.6 to 28.298.7<0.001
 Heart failure168222132.429.0 to 36.0
 Hematology/oncology3240145321.37.5 to 47.699.2<0.001
 Nephrotoxins417,786168112.26.2 to 22.798.7<0.001
 Hospital acquired, unspecified521,948,760257,87820.917.2 to 25.299.9<0.001
Continent
 Australia and New Zealand9523,715182,40525.622.3 to 29.399.9<0.001
 Asia21286,37717,35815.68.7 to 26.499.9<0.001
 Europe51918,06872,39023.118.0 to 29.299.9<0.001
 America701,847,689296,65524.922.1 to 27.899.9<0.001
 Multiple continents310,062461649.422.9 to 76.399.9<0.001
World zonea
 Australia and New Zealand9523,715182,40525.622.3 to 29.399.9<0.001
 Eastern Asia17258,16114,79414.77.0 to 28.299.9<0.001
 Western Asia225,989200616.73.3 to 54.399.3<0.001
 South Asia2222755823.77.5 to 54.499.4<0.001
 Eastern Europe2260063922.09.5 to 43.398.9<0.001
 Western Europe15161,19814,72520.112.1 to 31.599.9<0.001
 Northern Europe12607,956889414.75.5 to 33.699.9<0.001
 Southern Europe1824,080654631.523.1 to 41.399.5<0.001
 Multi-zone Europe4122,2344158632.528.3 to 37.099.6<0.001
 North America641,843,814295,55424.521.7 to 27.599.9<0.001
 South America63875110129.619.1 to 42.798.3<0.001
 Multiple zones310,062461649.422.9 to 76.399.9<0.001
Latitude
 North1383,057,543389,45422.620.2 to 25.299.9<0.001
 South15527,590183,50627.024.2 to 30.099.8<0.001
 North and South177846459.656.2 to 63.0
Country income classificationb
 Low income1104739938.135.2 to 41.1
 Lower middle income1118015913.511.6 to 15.5
 Upper middle income20248,71814,33519.510.4 to 33.799.9<0.001
 High income1303,313,430553,20323.821.4 to 26.499.9<0.001
 Not available221,536532825.123.6 to 26.780.40.02
Country total health expenditure (% of GDP)c
 <58222,178782314.57.2 to 26.999.8<0.001
 5–10681,406,796258,63622.319.6 to 25.399.9<0.001
 >10761,935,401301,63725.222.3 to 28.399.9<0.001
 Not available221,536532825.123.6 to 26.780.4<0.001
  • KDIGO, Kidney Disease Improving Global Outcomes; GDP, gross domestic product.

  • a According to the United Nations geo-scheme classification (11).

  • b According to the World Bank's classification of income of countries (12).

  • c According to the World Health Organization (14).