Table 1.

Demographics of patients^a

	No AKI	Low BCR	High BCR	Low versus High
Number of patients	16 485	1704	1937
Age, years	65 (49–76)	75 (65–82)	79 (71–85)	<0.001
Male gender, %	56.1	55.3	45.1	<0.001
Re-admission, %	29.3	25.8	32.8	<0.001
Emergency admission, %	55.7	65.3	75.4	<0.001
ICU admission, %	12.3	28.4	22.8	<0.001
Mechanical ventilation, %	7.3	20.4	14.5	<0.001
Baseline Cr, mg/dL	1.01 (0.81–1.08)	1.00 (0.79–1.04)	0.82 (0.78–1.03)	<0.001
Baseline Cr, (μmol/L)	89 (71–95)	88 (70–92)	72 (69–91)
Operation, %	36.7	33.6	23.1	<0.001
Admission units, %				<0.001
General medicine	19.6	30.7	45.6
Cardiology	12.9	7.8	6.6
Gastroenterology	3.1	5.4	4.2
Hematology	1.6	2.6	2.6
Neurology	4.9	1.8	2.1
Oncology	7.6	5.6	7.8
Renal medicine	0.6	5.7	3.0
Respiratory medicine	3.6	3.2	3.8
Stroke unit	2.9	3.0	2.5
Other medical units	3.7	1.4	1.9
Cardiac surgery	4.5	8.7	4.6
General surgery	12.7	8.3	5.6
Neurosurgery	5.4	0.9	1.3
Orthopedics	4.6	2.2	2.6
Thoracic surgery	4.0	1.8	1.2
Urology	3.0	5.0	0.9
Vascular surgery	2.7	4.3	2.9
Other surgical units	2.6	1.3	0.8
Admission to AKI, days	N/A	2 (1–4)	2 (1–4)	0.18
Cr at AKI occurrence, mg/dL	N/A	1.74 (1.43–2.33)	1.64 (1.32–2.05)	<0.001
Cr at AKI occurrence, (μmol/L)	N/A	153 (126–205)	144 (116–180)
BUN at AKI occurrence, mg/dL	N/A	28.0 (22.1–36.1)	44.5 (34.7–62.2)	<0.001
Urea, mmol/L	N/A	10.0 (7.9–12,9)	15.9 (12.4–22.2)
BUN/Cr ratio	N/A	15.8 (13.3–17.8)	26.1 (22.7–31.7)	<0.001
Urea mmol/L/Cr μmol/L	N/A	0.064 (0.054–0.072)	0.106 (0.092–0.129)

^aAdmission to AKI, duration between hospital admission and AKI occurrence; Cr, creatinine; N/A, not available.