Characteristics of the 154 studies that used a KDIGO-equivalent AKI definition
| All Studies | Studies of Adults | Studies of Children | |
|---|---|---|---|
| No. of studies | 154 | 130 | 24 |
| Sample size | 22,220 (95–1,126,636) | 26,240 (509–1,126,636) | 593 (95–3396) |
| Percentage of male participants | 63 (28–100) | 65 (28–100) | 56 (49–79) |
| Age of participants (yr) | 51.6 (0.0–80.3)a | 60.6 (25.5–80.3) | 4.7 (0.0–11.4)a |
| Studies by clinical setting | |||
| Community acquired | 7 (5) | 6 (5) | 1 (4) |
| Critical care | 41 (27) | 32 (25) | 9 (38) |
| Cardiac surgery | 42 (27) | 35 (27) | 7 (29) |
| Trauma | 4 (2) | 4 (3) | 0 (0) |
| Heart failure | 1 (1) | 1 (1) | 0 (0) |
| Hematology/oncology | 3 (2) | 3 (2) | 0 (0) |
| Nephrotoxins | 4 (2) | 2 (1) | 2 (8) |
| Hospital acquired, unspecified | 52 (34) | 47 (36) | 5 (21) |
| Studies by continent | |||
| Australia and New Zealand | 9 (6) | 9 (7) | 0 (0) |
| Asia | 21 (14) | 18 (14) | 3 (13) |
| Europe | 51 (33) | 45 (35) | 6 (25) |
| America | 70 (45) | 55 (42) | 15 (62) |
| Africa | 0 (0) | 0 (0) | 0 (0) |
| Multiple continents | 3 (2) | 3 (2) | 0 (0) |
| Studies by world zoneb | |||
| Australia and New Zealand | 9 (6) | 9 (7) | 0 (0) |
| Eastern Asia | 17 (11) | 15 (12) | 2 (8) |
| Western Asia | 2 (1) | 1 (1) | 1 (4) |
| Southern Asia | 2 (1) | 2 (2) | 0 (0) |
| South East Asia | 0 (0) | 0 (0) | 0 (0) |
| Eastern Europe | 2 (1) | 1 (1) | 1 (4) |
| Western Europe | 15 (10) | 13 (10) | 2 (8) |
| Northern Europe | 12 (8) | 10 (8) | 2 (8) |
| Southern Europe | 18 (11) | 17 (13) | 1 (4) |
| Multi-zone Europe | 4 (3) | 4 (3) | 0 (0) |
| North America | 64 (42) | 50 (38) | 14 (60) |
| South America | 6 (4) | 5 (3) | 1 (4) |
| North Africa | 0 (0) | 0 (0) | 0 (0) |
| Western Africa | 0 (0) | 0 (0) | 0 (0) |
| Multiple zones | 3 (2) | 3 (2) | 0 (0) |
| Studies by latitude | |||
| North | 138 (89) | 115 (88) | 23 (96) |
| South | 15 (10) | 14 (11) | 1 (4) |
| North and South | 1 (1) | 1 (1) | 0 (0) |
| Country income classificationc | |||
| Low income | 1 (1) | 1 (1) | 0 (0) |
| Lower middle income | 1 (1) | 1 (1) | 0 (0) |
| Upper middle income | 20 (13) | 16 (12) | 4 (17) |
| High income | 130 (84) | 110 (85) | 20 (83) |
| Not available | 2 (1) | 2 (1) | 0 (0) |
| Country total health expenditure (% of GDP)d | |||
| <5 | 8 (5) | 7 (5) | 1 (4) |
| 5–10 | 68 (45) | 58 (45) | 10 (42) |
| >10 | 76 (49) | 63 (48) | 13 (54) |
| Not available | 2 (1) | 2 (2) | 0 (0) |
Data are presented as the mean (range) or n (%). KDIGO, Kidney Disease Improving Global Outcomes; GDP, gross domestic product.
↵a A zero value indicates newborns.
↵b According to the United Nations geo-scheme classification (11).
↵c According to the World Bank's classification of income of countries (12).
↵d According to the World Health Organization (14).