Baseline characteristics of the enroled patients stratified by the ACAG value in the two cohorts
| MIMIC-IV cohort (n=808) | eICU-CRD cohort (n=700) | |||||||
| Overall (n=808) | Normal ACAG (n=416) | Higher ACAG (n=392) | p value | Overall (n=700) | Normal ACAG (n=353) | Higher ACAG (n=347) | p value | |
| Demographic characteristics | ||||||||
| Age | 70 (60, 80) | 71 (61, 81) | 70 (60, 79) | 0.3 | 67 (57, 76) | 68 (57, 77) | 67 (57, 75) | 0.2 |
| Sex | 0.2 | |||||||
| Female | 347 (43%) | 188 (45%) | 159 (41%) | 255 (36%) | 130 (37%) | 125 (36%) | ||
| Male | 461 (57%) | 228 (55%) | 233 (59%) | 445 (64%) | 223 (63%) | 222 (64%) | ||
| Weight/BMI* | 80 (68, 95) | 79 (67, 94) | 81 (68, 97) | 0.2 | 28 (24, 33) | 28 (24, 33) | 28 (24, 33) | 0.6 |
| Ethnicity | 0.3 | 0.016* | ||||||
| White | 497 (62%) | 255 (61%) | 242 (62%) | 531 (76%) | 276 (78%) | 255 (73%) | ||
| Black | 71 (8.8%) | 34 (8.2%) | 37 (9.4%) | 83 (12%) | 32 (9.1%) | 51 (15%) | ||
| Hispanic | 19 (2.4%) | 12 (2.9%) | 7 (1.8%) | 32 (4.6%) | 14 (4.0%) | 18 (5.2%) | ||
| Asian | 18 (2.2%) | 13 (3.1%) | 5 (1.3%) | 19 (2.7%) | 15 (4.2%) | 4 (1.2%) | ||
| Others/unknown | 203 (25%) | 102 (25%) | 101 (26%) | 35 (5.0%) | 16 (4.5%) | 19 (5.5%) | ||
| Comorbidities | ||||||||
| AMI | 349 (43%) | 187 (45%) | 162 (41%) | 0.3 | 270 (39%) | 152 (43%) | 118 (34%) | 0.014* |
| Hypertension | 241 (30%) | 143 (34%) | 98 (25%) | 0.004* | 365 (52%) | 186 (53%) | 179 (52%) | 0.8 |
| Cardiomyopathy | 206 (25%) | 105 (25%) | 101 (26%) | 0.9 | 119 (17%) | 69 (20%) | 50 (14%) | 0.070 |
| Atrial fibrillation | 393 (49%) | 199 (48%) | 194 (49%) | 0.6 | 144 (21%) | 77 (22%) | 67 (19%) | 0.4 |
| VHD | 293 (36%) | 150 (36%) | 143 (36%) | >0.9 | 99 (14%) | 64 (18%) | 35 (10%) | 0.002* |
| AKI/ARF* | 573 (71%) | 259 (62%) | 314 (80%) | <0.001* | 323 (46%) | 150 (42%) | 173 (50%) | 0.051 |
| COPD | 71 (8.8%) | 41 (9.9%) | 30 (7.7%) | 0.3 | 101 (14%) | 53 (15%) | 48 (14%) | 0.7 |
| Diabetes | 283 (35%) | 116 (28%) | 167 (43%) | <0.001* | 158 (23%) | 70 (20%) | 88 (25%) | 0.080 |
| Malignancy | 80 (9.9%) | 38 (9.1%) | 42 (11%) | 0.5 | 16 (2.3%) | 6 (1.7%) | 10 (2.9%) | 0.3 |
| SOFA | 8 (5, 11) | 7 (4, 10) | 9 (6, 12) | <0.001* | 8 (6, 11) | 7 (5, 10) | 9 (7, 12) | <0.001* |
| Vital signs | ||||||||
| Heart rate | 90 (77, 108) | 87 (74, 102) | 93 (80, 111) | <0.001* | 91 (78, 108) | 90 (77, 105) | 93 (78, 111) | 0.088 |
| Respiratory rate | 20 (17, 24) | 20 (16, 23) | 21 (17, 26) | <0.001* | 20 (17, 25) | 19 (16, 24) | 20 (17, 25) | 0.083 |
| Systolic BP | 111 (97, 129) | 114 (99, 127) | 109 (95, 129) | 0.2 | 107 (91, 122) | 107 (92, 121) | 107 (90, 126) | 0.8 |
| Diastolic BP | 66 (54, 79) | 66 (54, 79) | 66 (54, 78) | 0.5 | 62 (50, 75) | 62 (50, 73) | 62 (50, 77) | 0.3 |
| Mean BP | 79 (68, 91) | 79 (69, 91) | 78 (66, 91) | 0.4 | 77 (65, 89) | 76 (67, 88) | 78 (64, 91) | 0.4 |
| SpO2 | 97 (94, 100) | 98 (94, 100) | 97(93, 100) | 0.12 | 97 (93, 100) | 97 (94, 100) | 98 (93, 100) | >0.9 |
| Laboratory data | ||||||||
| White blood cell | 13 (9, 17) | 12 (9, 17) | 13 (9, 18) | 0.001* | 12 (9, 18) | 12 (9, 16) | 13 (9, 20) | 0.002* |
| Haemoglobin | 11.5 (9.8, 13.4) | 11.7 (10.1, 13.5) | 11.4 (9.6, 13.1) | 0.045* | 12.1 (10.1, 13.9) | 12.2 (10.3, 14.0) | 11.8 (9.8, 13.7) | 0.2 |
| Platelet | 211 (152, 278) | 210 (154, 278) | 213 (149, 278) | 0.8 | 196 (145, 260) | 203 (151, 253) | 192 (139, 268) | 0.4 |
| Sodium | 138 (134, 141) | 138 (135, 141) | 137 (133, 141) | 0.2 | 137 (134, 141) | 137 (135, 140) | 138 (133, 141) | >0.9 |
| Potassium | 4.4 (3.9, 5.0) | 4.3 (3.8, 4.7) | 4.6 (3.9, 5.1) | <0.001* | 4.2 (3.7, 4.9) | 4.1 (3.7, 4.7) | 4.4 (3.7, 5.2) | <0.001* |
| Chloride | 103 (98, 107) | 104 (100,108) | 101 (96, 106) | <0.001* | 103 (98, 107) | 104 (100, 108) | 101 (96, 105) | <0.001* |
| Bicarbonate | 20 (17, 23) | 22 (20, 25) | 18 (15, 21) | <0.001* | 22 (18, 25) | 24 (21, 27) | 19 (16, 22) | <0.001* |
| AG | 13 (9, 17) | 12 (9, 17) | 13 (9, 18) | 0.001* | 167 (13, 21) | 13 (12, 15) | 21 (18, 24) | <0.001* |
| Albumin | 3.3 (2.9, 3.7) | 3.4 (3.0, 3.7) | 3.2 (2.7, 3.6) | <0.001* | 3.0 (2.6, 3.5) | 3.1 (2.8, 3.6) | 2.9 (2.5, 3.4) | <0.001* |
| ACAG | 20.0 (17.0, 23.5) | 17.1 (15.3, 18.5) | 23.5 (21.8, 26.5) | <0.001* | 19.9 (16.7, 24.2) | 16.7 (14.8, 18.3) | 24.2 (21.9, 28.0) | <0.001* |
| Creatine | 1.4 (1.0, 2.3) | 1.2 (0.9, 1.7) | 1.8 (1.3, 2.9) | <0.001* | 1.5 (1.1, 2.4) | 1.3 (0.9, 1.8) | 1.8 (1.3, 2.8) | <0.001* |
| Bilirubin | 0.7 (0.4, 1.3) | 0.7 (0.4, 1.0) | 0.8 (0.5, 1.5) | <0.001* | 0.8 (0.5, 1.4) | 0.8 (0.5, 1.3) | 0.9 (0.5, 1.6) | 0.055 |
| Outcomes | ||||||||
| LOS in the ICU | 5 (3, 9) | 5 (3, 9) | 5 (3, 9) | 0.5 | 5 (3, 9) | 5 (3, 8) | 5 (3, 9) | 0.3 |
| LOS in hospital | 10 (5, 17) | 10 (6, 17) | 10 (5, 18) | 0.3 | 8 (5, 14) | 9 (5, 15) | 8 (4, 14) | 0.017* |
| ICU death | 231 (29%) | 85 (20%) | 146 (37%) | <0.001* | 211 (30%) | 87 (25%) | 124 (36%) | 0.001* |
| Hospital death | 289 (36%) | 122 (29%) | 167 (43%) | <0.001* | 260 (37%) | 102 (29%) | 158 (46%) | <0.001* |
| 28-day death† | 315 (39%) | 126 (30%) | 189 (48%) | <0.001* | ||||
| 28-day free from the ICU duration† | 17 (0, 24) | 20 (2, 25) | 9 (0, 23) | <0.001* | ||||
p<0.05*
* Body weight and acute kidney injury are shown for the MIMIC-IV cohort, whereas body mass index and acute renal failure are presented for the eICU-CRD cohort because of data availability
†28-day all-cause mortality and 28-day free from the ICU duration were reported for the MIMIC-IV cohort.
BMI, body mass index; AMI, acute myocardial infarction; AKI, acute kidney injury; ARF, acute renal failure; COPD, chronic obstructive pulmonary disease; SOFA, sequential organ failure assessment; BP, blood pressure; AG, anion gap; ACAG, albumin-corrected anion gap; LOS, length of stay; ICU, intensive care unit.