Emergency Medicine International

Research Article

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 4

Subgroup analysis of the associations between 90-day all-cause mortality and the RA level.


	No. of patients	HR (95% CI)	P value

Age (year)
<77.7	3180	1.25 (1.21, 1.28)	<0.0001
≥77.7	3181	1.27 (1.23, 1.30)	<0.0001
Gender
Female	2960	1.24 (1.21, 1.28)	<0.0001
Male	3401	1.26 (1.22, 1.30)	<0.0001
Ethnicity
White	4642	1.25 (1.22, 1.29)	<0.0001
Black	586	1.23 (1.16, 1.30)	<0.0001
Other	1133	1.25 (1.20, 1.30)	<0.0001
Sepsis
No	5104	1.23 (1.20, 1.26)	<0.0001
Yes	1257	1.23 (1.18, 1.28)	<0.0001
Heart rate (beats/minute)
<83	3173	1.29 (1.25, 1.33)	<0.0001
≥83	3174	1.21 (1.18, 1.24)	<0.0001
SBP (mmHg)
<114	3171	1.22 (1.20, 1.26)	<0.0001
≥114	3171	1.24 (1.19, 1.29)	<0.0001
DBP (mmHg)
<56	3170	1.24 (1.21, 1.27)	<0.0001
≥56	3172	1.25 (1.21, 1.29)	<0.0001
MAP (mmHg)
<73	3173	1.25 (1.21, 1.28)	<0.0001
≥73	3174	1.23 (1.19, 1.27)	<0.0001
Respiratory rate (times/minute)
<19	3170	1.26 (1.22, 1.30)	<0.0001
≥19	3170	1.23 (1.20, 1.27)	<0.0001
SpO₂ (%)
<97.5	3168	1.27 (1.24, 1.31)	<0.0001
≥97.5	3174	1.23 (1.19, 1.26)	<0.0001
Temperature (°C)
<36.7	3139	1.25 (1.22, 1.28)	<0.0001
≥36.7	3146	1.24 (1.20, 1.28)	<0.0001
Bicarbonate (mg/dL)
<24	2654	1.21 (1.18, 1.25)	<0.0001
≥24	3702	1.27 (1.24, 1.30)	<0.0001
Bilirubin (mg/dL)
<0.6	2245	1.26 (1.22, 1.30)	<0.0001
≥0.6	3204	1.26 (1.22, 1.29)	<0.0001
Glucose (mg/dL)
<166	3169	1.26 (1.23, 1.30)	<0.0001
≥166	3186	1.24 (1.21, 1.28)	<0.0001
WBC (10⁹/L)
<11.5	3167	1.27 (1.23, 1.30)	<0.0001
≥11.5	3194	1.22 (1.19, 1.26)	<0.0001
Hematocrit (%)
<34.4	3143	1.24 (1.21, 1.28)	<0.0001
≥34.4	3215	1.27 (1.23, 1.31)	<0.0001
Hemoglobin (g/dL)
<11.4	3096	1.23 (1.20, 1.26)	<0.0001
≥11.4	3262	1.27 (1.23, 1.31)	<0.0001
Platelet (10⁹/L)
<216	3177	1.25 (1.22, 1.29)	<0.0001
≥216	3180	1.24 (1.21, 1.28)	<0.0001
Sodium (mg/dL)
<141	3147	1.24 (1.20, 1.27)	<0.0001
≥141	3209	1.26 (1.22, 1.29)	<0.0001
Potassium (mmol/L)
<4.6	2960	1.26 (1.22, 1.29)	<0.0001
≥4.6	3398	1.24 (1.21, 1.28)	<0.0001
Chloride (mg/dL)
<107	2837	1.26 (1.22, 1.30)	<0.0001
≥107	3519	1.25 (1.22, 1.28)	<0.0001
PT (second)
<15.3	3032	1.23 (1.19, 1.28)	<0.0001
≥15.3	3083	1.24 (1.21, 1.27)	<0.0001
INR
<1.4	2722	1.25 (1.20, 1.30)	<0.0001
≥1.4	3392	1.23 (1.20, 1.26)	<0.0001
APTT (second)
<35.2	3046	1.29 (1.24, 1.34)	<0.0001
≥35.2	3055	1.22 (1.20, 1.25)	<0.0001
Creatinine (mg/dL)
<1.5	2940	1.27 (1.23, 1.32)	<0.0001
≥1.5	3418	1.22 (1.19, 1.25)	<0.0001
BUN (mg/dL)
<34	3078	1.25 (1.21, 1.29)	<0.0001
≥34	3280	1.23 (1.20, 1.26)	<0.0001
Anion gap (mg/dL)
<17	3011	1.25 (1.21, 1.29)	<0.0001
≥17	3321	1.27 (1.24, 1.31)	<0.0001
Albumin (g/dL)
<3.1	2886	1.20 (1.17, 1.23)	<0.0001
≥3.1	3475	1.40 (1.29, 1.51)	<0.0001
RDW (%)
<15.1	3052	1.31 (1.25, 1.37)	<0.0001
≥15.1	3309	1.21 (1.18, 1.24)	<0.0001
Lactate (mmol/L)
<2.4	2290	1.25 (1.20, 1.29)	<0.0001
≥2.4	2406	1.20 (1.16, 1.23)	<0.0001
Sepsis
No	5104	1.23 (1.20, 1.26)	<0.0001
Yes	1257	1.23 (1.18, 1.28)	<0.0001
Septic shock
No	5532	1.24 (1.21, 1.27)	<0.0001
Yes	829	1.21 (1.16, 1.27)	<0.0001
Congestive heart failure
No	3566	1.22 (1.19, 1.26)	<0.0001
Yes	2795	1.30 (1.26, 1.34)	<0.0001
Arrhythmia
No	3526	1.25 (1.21, 1.28)	<0.0001
Yes	2835	1.26 (1.22, 1.30)	<0.0001
Heart valve disease
No	5263	1.25 (1.23, 1.28)	<0.0001
Yes	1098	1.23 (1.16, 1.30)	<0.0001
Peripheral vascular disease
No	5544	1.26 (1.23, 1.29)	<0.0001
Yes	817	1.18 (1.12, 1.25)	<0.0001
Hypertension
No	2268	1.23 (1.19, 1.27)	<0.0001
Yes	4093	1.25 (1.22, 1.29)	<0.0001
Nervous system diseases
No	5525	1.26 (1.23, 1.28)	<0.0001
Yes	836	1.18 (1.10, 1.26)	<0.0001
Diabetes
No	4727	1.24 (1.21, 1.26)	<0.0001
Yes	1634	1.31 (1.25, 1.38)	<0.0001
Hypothyroidism
No	5524	1.25 (1.22, 1.27)	<0.0001
Yes	837	1.25 (1.18, 1.32)	<0.0001
Renal failure
No	4569	1.27 (1.24, 1.30)	<0.0001
Yes	1792	1.20 (1.15, 1.24)	<0.0001
Metastatic cancer
No	5999	1.25 (1.23, 1.28)	<0.0001
Yes	362	1.08 (1.00, 1.16)	0.0465
Solid tumor
No	6073	1.25 (1.22, 1.27)	<0.0001
Yes	288	1.30 (1.20, 1.41)	<0.0001
Coagulopathy	2952	1.27 (1.20, 1.35)
No	5270	1.26 (1.23, 1.29)	<0.0001
Yes	1091	1.20 (1.15, 1.25)	<0.0001
Obesity
No	6122	1.25 (1.22, 1.27)	<0.0001
Yes	239	1.36 (1.18, 1.57)	<0.0001
Electrolyte disorder
No	3515	1.28 (1.24, 1.31)	<0.0001
Yes	2846	1.22 (1.18, 1.25)	<0.0001
Hemorrhagic anemia
No	6168	1.25 (1.22, 1.27)	<0.0001
Yes	193	1.27 (1.12, 1.46)	0.0004
Alcohol abuse
No	6147	1.25 (1.22, 1.27)	<0.0001
Yes	214	1.28 (1.11, 1.46)	0.0004
SAPSII
<44	3158	1.27 (1.22, 1.32)	<0.0001
≥44	3203	1.17 (1.14, 1.20)	<0.0001
SOFA
<5	2662	1.29 (1.23, 1.36)	<0.0001
≥5	3699	1.20 (1.17, 1.23)	<0.0001
AKI stage
I	1514	1.30 (1.25, 1.35)	<0.0001
II	944	1.18 (1.10, 1.25)	<0.0001
III	3903	1.24 (1.21, 1.27)	<0.0001

SBP: systolic blood pressure; DBP: diastolic blood pressure; MAP: mean arterial pressure; RA: the ratio of red cell volume distribution width to albumin; RDW: red cell volume distribution width; CRP: C-reactive protein; PT: prothrombin time; INR: international normalized ratio; APTT: activated partial thromboplastin time; BUN: blood urea nitrogen; COPD: chronic obstructive pulmonary disease; ARDS: acute respiratory distress syndrome; AKI: acute kidney injury; SAPSII: simplified acute physiology score II; SOFA: sequential organ failure assessment; ICU: intensive care unit.