Table 1.
Characteristics of patients with AKI and no AKI grouped by country income level
| Variables | Low and lower-middle income country patients |
Upper-middle income country patients |
High income country patients |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| All | AKI | No AKI | SMD | All | AKI | No AKI | SMD | All | AKI | No AKI | SMD | |
| Total count | 5238 | 2789 | 2449 | --- | 1833 | 704 | 1129 | --- | 25,049 | 7645 | 17,404 | --- |
| Demographics | ||||||||||||
| Age, y, median (IQR) | 60 (50–70) | 62 (52–71) | 60 (49–70) | −0.13 | 58.1 (47–69) | 63 (52–71) | 55.1 (43.1–68) | −0.35 | 61 (51–70) | 63 (54–70) | 60 (50–69) | −0.19 |
| Female (%) | 1816 (35) | 933 (33) | 883 (36) | 0.06 | 650 (35) | 252 (36) | 398 (35) | 0.01 | 8172 (33) | 2131 (28) | 6041 (35) | 0.15 |
| AKI grades and KRT, n (%) | ||||||||||||
| AKI grade 1 | 916 (17) | 916 (33) | 0 (0) | --- | 145 (8) | 145 (21) | 0 (0) | --- | 1973 (8) | 1973 (26) | 0 (0) | --- |
| AKI grade 2 | 463 (9) | 463 (17) | 0 (0) | --- | 73 (4) | 73 (10) | 0 (0) | --- | 841 (3) | 841 (11) | 0 (0) | --- |
| AKI grade 3 with RRT | 1410 (27) | 1410 (51)a | 0 (0) | --- | 486 (27) | 486 (69)a | 0 (0) | --- | 4831 (19) | 4831 (63)a | 0 (0) | --- |
| AKI grade 3 w/o RRT | 658 (24)a | 169 (24)a | 1414 (18)aa | |||||||||
| KRT | 752 (14) | 752 (27)a | 0 (0) | --- | 317 (17) | 317 (45)a | 0 (0) | --- | 3417 (14) | 3417 (45)a | 0 (0) | --- |
| KRT/all grade 3 | 53% | 65% | 71% | |||||||||
| Calculated as a proportion of total AKIa | Calculated as a proportion of total AKIa | Calculated as a proportion of total AKIa | ||||||||||
| Comorbiditiesb, n (%) | ||||||||||||
| Chronic kidney disease | 138 (3) | 100 (4) | 38 (2) | 0.13 | 139 (8) | 105 (15) | 34 (3) | 0.45 | 2047 (8) | 1112 (15) | 935 (5) | 0.31 |
| Chronic cardiac disease | 523 (10) | 291 (10) | 232 (9) | 0.03 | 255 (14) | 133 (19) | 122 (11) | 0.24 | 3873 (15) | 1410 (18) | 2463 (14) | 0.11 |
| Chronic pulmonary disease | 168 (3) | 87 (3) | 81 (3) | 0.01 | 102 (6) | 51 (7) | 51 (5) | 0.13 | 2463 (10) | 756 (10) | 1707 (10) | 0.00 |
| Hypertension | 2451 (47) | 1360 (49) | 1091 (45) | 0.08 | 950 (52) | 435 (62) | 515 (46) | 0.36 | 9681 (39) | 3115 (41) | 6566 (38) | 0.19 |
| Dementia | 20 (0) | 9 (0) | 11 (0) | 0.02 | 23 (1) | 6 (1) | 17 (2) | 0.06 | 249 (1) | 80 (1) | 169 (1) | 0.01 |
| Liver disease | 34 (1) | 21 (1) | 13 (1) | 0.03 | 26 (1) | 17 (2) | 9 (1) | 0.14 | 801 (3) | 286 (4) | 515 (3) | 0.04 |
| Malnutrition | 16 (0) | 5 (0) | 11 (0) | 0.05 | 26 (1) | 14 (2) | 12 (1) | 0.08 | 238 (1) | 89 (1) | 149 (1) | 0.03 |
| Obesity | 113 (2) | 57 (2) | 56 (2) | 0.02 | 517 (28) | 216 (31) | 301 (27) | 0.14 | 6131 (24) | 1923 (25) | 4208 (24) | 0.03 |
| Signs and symptoms on admission, n (%) | ||||||||||||
| Altered consciousness/confusion | 137 (3) | 85 (3) | 52 (2) | 0.06 | 115 (6) | 49 (7) | 66 (6) | 0.12 | 2563 (10) | 894 (12) | 1669 (10) | 0.10 |
| Diarrhea | 185 (4) | 99 (4) | 86 (4) | 0.00 | 256 (14) | 95 (13) | 161 (14) | 0.03 | 4981 (20) | 1424 (19) | 3557 (20) | 0.01 |
| Fever | 3756 (72) | 1994 (71) | 1762 (72) | 0.02 | 1135 (62) | 396 (56) | 739 (65) | 0.01 | 17,996 (72) | 5393 (71) | 12,603 (72) | 0.03 |
| Vomiting/nausea | 268 (5) | 139 (5) | 129 (5) | 0.01 | 160 (9) | 47 (7) | 113 (10) | 0.09 | 4045 (16) | 1137 (15) | 2908 (17) | 0.02 |
| Muscle aches/joint pain | 386 (7) | 189 (7) | 197 (8) | 0.05 | 476 (26) | 145 (21) | 331 (29) | 0.14 | 5880 (23) | 1617 (21) | 4263 (24) | 0.04 |
| Headache | 184 (4) | 96 (3) | 88 (4) | 0.01 | 279 (15) | 69 (10) | 210 (19) | 0.22 | 3116 (12) | 810 (11) | 2306 (13) | 0.06 |
| Cough | 1686 (32) | 859 (31) | 827 (34) | 0.07 | 1009 (55) | 356 (51) | 653 (58) | 0.00 | 16,925 (68) | 4956 (65) | 11,969 (69) | 0.02 |
| Shortness of breath | 3904 (75) | 2155 (77) | 1749 (71) | 0.12 | 1,144 (62) | 442 (63) | 702 (62) | 0.18 | 19,462 (78) | 5773 (76) | 13,689 (79) | 0.01 |
| Observations on admission, median (IQR) | ||||||||||||
| Temperature, C | 36.7 (36.7–37) | 36.7 (36.7–37) | 36.7 (36.7–37.1) | 0.10 | 36.8 (36.2–37.7) | 37 (36.3–37.7) | 36.8 (36.2–37.6) | −0.08 | 37.5 (36.8–38.3) | 37.5 (36.8–38.4) | 37.5 (36.8–38.3) | −0.04 |
| Systolic BP, mmHg | 130 (117–143) | 130 (117–145) | 130 (118–141) | −0.03 | 130 (116–144) | 129 (111–145) | 130 (119–143) | 0.08 | 127 (112–142) | 127 (110–144) | 127 (112–142) | −0.01 |
| Diastolic BP, mmHg | 75 (68–83) | 75 (66–84) | 75 (69–82) | −0.02 | 76 (66–85) | 74 (63–85) | 77 (68–85) | 0.18 | 73 (63–82) | 71 (60–81) | 73 (64–82) | 0.14 |
| Heart rate, BPM | 91 (82–103) | 94 (82.5–107) | 90 (81–100) | −0.18 | 91 (80–106) | 94 (80–108) | 90 (79–104) | −0.21 | 94 (82–108) | 95 (82–109) | 94 (82–108) | −0.05 |
| Respiratory rate, per min | 24 (20–29) | 24 (21–30) | 23 (20–28) | −0.23 | 22 (18–28) | 24 (20–30) | 21 (18–26) | −0.38 | 24 (20–30) | 24 (20–31) | 24 (20–30) | −0.02 |
| Oxygen saturation, % | 93 (90–96) | 92.4 (89–96) | 94 (90–96) | 0.15 | 94 (90–96) | 92 (88–96) | 94 (91–97) | 0.32 | 93.3 (89–96) | 93 (88–96) | 94 (89.8–96) | 0.14 |
| Laboratory results on admission, median (IQR) | ||||||||||||
| Potassium (mmol/l) | 4.2 (3.7–4.6) | 4.2 (3.7–4.6) | 4.1 (3.7–4.5) | −0.14 | 4.1 (3.7–4.5) | 4.2 (3.8–4.6) | 4.1 (3.7–4.5) | −0.24 | 4.1 (3.7–4.4) | 4.2 (3.8–4.6) | 4 (3.7–4.4) | −0.24 |
| sCr (μmol/l) | 88.4 (70.7–132.6) | 97.2 (70.7–177.5) | 84 (68.1–106.1) | −0.48 | 87.8 (67.4–117.6) | 100.8 (71.5–150.5) | 83.1 (66.1–102.6) | −0.48 | 84.9 (67.2–111) | 98 (74.3–153) | 80.4 (65–101) | −0.50 |
| eGFR (ml/min per 1.73 m2) | 73 (44.2–96.5) | 64 (30.9–93.9) | 80.4 (57.2–98.7) | 0.45 | 78 (52.2–99.5) | 61.6 (37–93.1) | 84.3 (63.4–102.4) | 0.58 | 80.7 (55.9–98) | 66.3 (36.8–90.6) | 85.3 (63.9–100.4) | 0.59 |
| Hemoglobin (g/l) | 128 (111–141) | 126 (109–140) | 129 (115–142) | 0.17 | 135 (123–148) | 130 (116.2–145) | 138 (126–150) | 0.38 | 135 (120–147) | 131 (114–145) | 136 (122–148) | 0.26 |
| Sodium (mmol/l) | 137 (134–141) | 138 (134–142) | 137 (133.8–141) | −0.10 | 137 (134.3–140) | 137 (134–140) | 137 (135–140) | 0.01 | 136 (133–139) | 136 (133–139) | 136 (133–139) | 0.01 |
| Admission Treatment, n (%) | ||||||||||||
| Antiviral and COVID-19 targeting agents | 2633 (50) | 1464 (52) | 1169 (48) | 0.09 | 256 (14) | 108 (15) | 148 (13) | 0.16 | 11,066 (44) | 2663 (35) | 8403 (48) | 0.27 |
| Antibiotic agents | 4733 (90) | 2640 (95) | 2093 (85) | 0.30 | 1399 (76) | 506 (72) | 893 (79) | 0.34 | 22,631 (90) | 7145 (93) | 15,486 (89) | 0.19 |
| Antifungal agents | 133 (3) | 86 (3) | 47 (2) | 0.07 | 205 (11) | 127 (18) | 78 (7) | 0.41 | 4119 (16) | 1865 (24) | 2254 (13) | 0.34 |
| Corticosteroids | 3699 (71) | 2183 (78) | 1516 (62) | 0.36 | 1180 (64) | 455 (65) | 725 (64) | 0.19 | 12,018 (48) | 3907 (51) | 8111 (47) | 0.10 |
| Invasive mechanical ventilation | 4851 (93) | 2668 (96) | 2183 (89) | 0.25 | 1060 (58) | 557 (79) | 503 (45) | 1.12 | 16,769 (67) | 6582 (86) | 10,187 (59) | 0.65 |
| Complicationsb, n (%) | ||||||||||||
| Bacterial pneumonia | 192 (4) | 120 (4) | 72 (3) | −0.05 | 478 (26) | 266 (38) | 212 (19) | 0.60 | 5582 (22) | 2044 (27) | 3538 (20) | 0.19 |
| Cardiac arrest | 570 (11) | 386 (14) | 184 (8) | −0.15 | 192 (10) | 140 (20) | 52 (5) | 0.61 | 1725 (7) | 1048 (14) | 677 (4) | 0.37 |
| Coagulation disorder | 167 (3) | 93 (3) | 74 (3) | −0.01 | 79 (4) | 68 (10) | 11 (1) | 0.49 | 2180 (9) | 937 (12) | 1243 (7) | 0.21 |
| Rhabdomyolysis | 1 (0) | 1 (0) | 0 (0) | −0.02 | 16 (1) | 12 (2) | 4 (0) | 0.17 | 429 (2) | 224 (3) | 205 (1) | 0.14 |
| Outcomes, n (%) | ||||||||||||
| Transferred | 244 (5) | 89 (3) | 155 (6) | 0.15 | 72 (4) | 31 (4) | 41 (4) | 0.04 | 2542 (10) | 925 (12) | 1617 (9) | 0.09 |
| Discharged | 1801 (34) | 494 (18) | 1307 (53) | 0.80 | 1113 (61) | 208 (30) | 905 (80) | 1.18 | 14,402 (57) | 2591 (34) | 11,811 (68) | 0.72 |
| Death | 3193 (61) | 2206 (79) | 987 (40) | 0.86 | 648 (35) | 465 (66) | 183 (16) | 1.17 | 8105 (32) | 4129 (54) | 3976 (23) | 0.68 |
| Length of stay (median, IQR) | 7 (4–11) | 8 (5–13) | 6 (4–9) | −0.36 | 14 (8–24) | 18.5 (11–30) | 12 (7–20) | −0.48 | 17 (10–28) | 20 (11–33) | 16 (10–25) | −0.26 |
AKI, acute kidney injury; BP, blood pressure; BPM, beats per minute; eGFR, estimated glomerular filtration rate (estimated using the CKD-EPI equation); IQR, interquartile range; RRT, renal replacement therapy; RRT, renal replacement therapy; sCr, serum creatinine; SMD, standardized mean difference.
a
Calculated as a proportion of total AKI.
b
Definitions of comorbidities, complications and outcomes from the CRFs are presented in Supplementary Table S2.