Prognostic Value of the Red Blood Cell Distribution Width-to-Albumin Ratio in Critically Ill Older Patients with Acute Kidney Injury: A Retrospective Database Study

Table 2

HRs (95% CIs) for all-cause mortality across groups of RA level.

RA level (ml/g)	Nonadjusted		Model I		Model II
	HR (95% CIs)	P value	HR (95% CIs)	P value	HR (95% CIs)	P value
Primary outcomes
90-day all-cause mortality
Continuous variable	1.25 (1.22, 1.27)	<0.0001	1.26 (1.24, 1.29)	<0.0001	1.17 (1.14, 1.20)	<0.0001
Tertiles
<4.35	1.0 (ref)		1.0 (ref)		1.0 (ref)
≥4.35, <5.68	1.54 (1.35, 1.75)	<0.0001	1.56 (1.37, 1.78)	<0.0001	1.22 (1.06, 1.41)	0.0049
≥5.68	2.80 (2.49, 3.16)	<0.0001	2.88 (2.56, 3.24)	<0.0001	1.90 (1.64, 2.19)	<0.0001
P trend	<0.0001		<0.0001		<0.0001
Secondary outcomes
30-day all-cause mortality
Continuous variable	1.25 (1.22, 1.28)	<0.0001	1.26 (1.23, 1.29)	<0.0001	1.15 (1.12, 1.19)	<0.0001
Tertiles
<4.35	1.0 (ref)		1.0 (ref)		1.0 (ref)
≥4.35, <5.68	1.46 (1.25, 1.70)	<0.0001	1.48 (1.27, 1.72)	<0.0001	1.15 (0.97, 1.35)	0.1019
≥5.68	2.62 (2.28, 3.01)	<0.0001	2.67 (2.33, 3.07)	<0.0001	1.70 (1.43, 2.01)	<0.0001
P trend	<0.0001		<0.0001		<0.0001
1-year all-cause mortality
Continuous variable	1.24 (1.22, 1.26)	<0.0001	1.25 (1.23, 1.27)	<0.0001	1.17 (1.15, 1.20)	<0.0001
Tertiles
<4.35	1.0 (ref)		1.0 (ref)		1.0 (ref)
≥4.35, <5.68	1.63 (1.46, 1.81)	<0.0001	1.65 (1.48, 1.84)	<0.0001	1.32 (1.18, 1.49)	<0.0001
≥5.68	2.72 (2.46, 3.01)	<0.0001	2.80 (2.53, 3.10)	<0.0001	1.95 (1.72, 2.20)	<0.0001
P trend	<0.0001		<0.0001		<0.0001

HR: hazard ratio; CI: confidence interval. Models were derived from Cox proportional hazards regression models. Nonadjusted model adjusting for none. Adjusted model I adjusting for age, ethnicity, and gender. Adjusted model II adjusting for congestive heart failure, arrhythmia, age, ethnicity, gender, diabetes, hypertension, renal failure, metastatic cancer, solid tumor, coagulopathy, obesity, electrolyte disorder, hemorrhagic anemia, anion gap, bicarbonate, creatinine, chloride, hematocrit, platelet, Potassium, APTT, INR, PT, BUN, SAPSII, SOFA, heart rate, systolic blood pressure, diastolic blood pressure, respiration rate, temperature, SpO₂, and white blood cell count.