Table 1.

For continuous variable, the numbers of measurements are listed (n = number in total cohort/number in AKI group/number in the no AKI group)

CharacteristicsTotal Cohort, n=1002, No. (%) or Median (Interquartile Range)AKI Group, n=294, No. (%) or Median (Interquartile Range)No AKI Group, n=708, No. (%) or Median (Interquartile Range)
Demographics and comorbidities
 Age, median, yr66 (53–76)69 (59–79)63 (51–74)
 Men619 (62%)208 (71%)411 (58%)
 Race
  White354 (35%)112 (38%)242 (34%)
  Black119 (12%)41 (14%)78 (11%)
  Other272 (27%)86 (29%)186 (26%)
  Unknown/declined257 (26%)55 (19%)202 (29%)
 Hypertensiona597 (60%)211 (72%)386 (55%)
 Diabetes mellitusa378 (38%)138 (47%)240 (34%)
 Congestive heart failurea131 (13%)67 (23%)64 (9%)
 COPDa81 (8%)36 (12%)45 (6%)
 Obesitya184 (18%)71 (24%)113 (16%)
 CKDb138 (14%)66 (22%)72 (10%)
 Kidney transplant recipient33 (3%)20 (7%)13 (2%)
Laboratory parametersc
 Baseline creatinine, mg/dl, n=1002/294/7080.9 (0.8–1.2)1.1 (0.9–1.4)0.9 (0.8–1.1)
 Admission creatinine, mg/dl, n=1002/294/7081.0 (0.8–1.3)1.2 (0.9–1.9)0.9 (0.8–1.1)
 Peak creatinine, mg/dl, n=1002/294/7081.1 (0.8–1.8)2.8 (1.8–5.0)0.9 (0.8–1.2)
 WBC×103/μl, n=1002/294/7086.9 (5.1–9.6)7.6 (5.5–10.7)6.7 (4.9–9.3)
 Hemoglobin, g/dl, n=1002/294/70813.4 (12.2–14.8)13.1 (11.5–14.5)13.6 (12.4–14.8)
 Platelets ×103/μl, n=1000/294/706207 (156–270)200 (146–258)213 (160–273)
 ALT, U/L, n=995/294/70134 (22–57)34 (21–54)35 (23–59)
 AST, U/L, n=986/291/69542 (28–65)46 (30–70)41 (27–63)
 Alkaline phosphatase, U/L, n=995/294/70174 (59–100)78 (59–105)73 (58–99)
 Total bilirubin, mg/dl, n=995/294/7010.6 (0.4–0.8)0.6 (0.4–0.9)0.6 (0.4–0.8)
 Albumin, g/dl, n=995/294/7013.2 (2.8–3.5)3.1 (2.7–3.4)3.2 (2.9–3.6)
 Prothrombin time, s, n=878/284/59413.3 (12.3–14.6)13.4 (12.6–15)13.2 (12.3–14.4)
 Procalcitonin, ng/ml, n=930/278/6520.17 (0.09–0.42)0.32 (0.16–0.69)0.14 (0.08–0.30)
 Troponin I, ng/ml, n=845/262/5830.03 (0.03–0.05)0.04 (0.03–0.12)0.03 (0.03–0.03)
 ESR, mm/h, n=716/216/50073 (49–99)76 (49–101)72 (48–97)
 CRP, mg/dl, n=748/228/52011 (6–19)14 (7–22)10 (5–17)
d-dimer, ng/ml, n=686/211/475442 (273–900)636 (339–1845)391 (248–772)
 Ferritin, ng/ml, n=784/240/544732 (339–1392)965 (500–1566)611 (292–1278)
 IL-6, pg/ml, n=181/91/9026 (10–58)33 (14–63)18 (9–50)
 LDH, U/L, n=866/263/603417 (319–545)478 (353–608)399 (311–515)
 Lactate, mmol/L, n=619/197/4221.6 (1.1–2.2)1.9 (1.3–3)1.5 (1.1–2.0)
 Creatine kinase, U/L, n=582/199/383144 (76–308)186 (86–409)130 (71–255)
 Urine protein, 1+, 2+, 3+, n=748/269/479505 (68%)207 (77%)298 (62%)
 Hematuria, 1+, 2+, 3+, n=748/269/479362 (48%)174 (65%)188 (39%)
 Fractional excretion of sodium <1%, n=148112 (76%)
 Urine granular casts >0/hpf, n=22046 (21%)
Hospital characteristics/outcomes
 NSAID usage in hospital278 (28%)104 (35%)174 (25%)
 Diuretic usage in hospital277 (28%)178 (61%)99 (14%)
 Anticoagulation usage in hospital675 (67%)201 (68%)474 (67%)
 Hydroxychloroquine usage in hospital695 (69%)231 (79%)464 (66%)
 ICU admission274 (27%)183 (62%)91 (13%)
 Mechanical ventilation261 (26%)179 (61%)82 (12%)
 Vasopressor usage261 (26%)183 (62%)78 (11%)
 Length of stay, d, n=971/281/6907 (3–17)17 (7–39)6 (3–12)
 Mortality172 (17%)118 (40%)54 (8%)
  • Among the laboratory parameters, WBCs, hemoglobin, platelets, ALT, AST, alkaline phosphatase, total bilirubin, albumin, procalcitonin, ESR, CRP, d-dimer, ferritin, and LDH were measured similarly in the AKI group and in the no AKI group (P>0.05), whereas prothrombin time, troponin I, IL-6, lactate, urine protein, and hematuria were measured more frequently in the AKI group than the no AKI group (P<0.05). P values were calculated using the Wilcoxon rank sum test for analysis of continuous variables and using the Fisher's exact test for analysis of dichotomous variables. All statistical analyses were performed using R 3.3.3. CKD indicates baseline creatinine of ≥1.5 mg/dl. COPD, chronic obstructive pulmonary disease; WBC, white blood cell; ALT, alanine aminotransferase; AST, aspartate aminotransferase; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; LDH, lactate dehydrogenase; hpf, high-power field; NSAID, nonsteroidal anti-inflammatory drug; ICU, intensive care unit.

  • a Obtained using International Classification of Diseases-9 and International Classification of Diseases-10 codes.

  • b A baseline creatinine prior to Emergency Department presentation was used in 320 patients (32%).

  • c All laboratory values were the first values obtained after Emergency Department presentation except for the fractional excretion of sodium <1% and urine granular casts >0/hpf, which were obtained within 3 days of the AKI event. Urine granular casts were detected using an automated system (iRiCELL; Beckman Coulter, Brea, CA), and they were manually verified by laboratory technicians.