Disease Markers

Research Article

Serum Anion Gap Predicts All-Cause Mortality in Critically Ill Patients with Acute Kidney Injury: Analysis of the MIMIC-III Database

Table 3

Subgroup analysis of the associations between anion gap and 30-day all-cause mortality.


Characteristic		HR (95% CI)	value	for interaction

CHF				0.0848
No	9399	1.12 (1.11, 1.13)	<0.0001
Yes	2174	1.09 (1.06, 1.12)	<0.0001
CAD				0.0056
No	8921	1.10 (1.09, 1.12)	<0.0001
Yes	2652	1.15 (1.12, 1.18)	<0.0001
AFIB				0.0023
No	8395	1.12 (1.11, 1.14)	<0.0001
Yes	3178	1.09 (1.07, 1.11)	<0.0001
Renal disease				0.4628
No	9326	1.12 (1.11, 1.13)	<0.0001
Yes	2247	1.11 (1.09, 1.14)	<0.0001
Liver disease				0.0436
No	10183	1.11 (1.09, 1.12)	<0.0001
Yes	1390	1.14 (1.11, 1.16)	<0.0001
Stroke				0.0184
No	10666	1.12 (1.11, 1.13)	<0.0001
Yes	907	1.07 (1.03, 1.11)	0.0002
Pneumonia				<0.0001
No	7997	1.14 (1.12, 1.15)	<0.0001
Yes	3576	1.06 (1.05, 1.08)	<0.0001
Respiratory failure				0.0002
No	6814	1.13 (1.12, 1.15)	<0.0001
Yes	4759	1.09 (1.08, 1.11)	<0.0001
ARDS				0.8864
No	11301	1.11 (1.10, 1.12)	<0.0001
Yes	272	1.13 (1.06, 1.19)	<0.0001
AKI stage				0.0005
Stage 1	2576	1.13 (1.10, 1.16)	<0.0001
Stage 2	1944	1.05 (1.02, 1.09)	0.0032
Stage 3	7053	1.11 (1.10, 1.13)	<0.0001
Albumin (g/dL)				0.3737
<3.2	5614	1.11 (1.10, 1.13)	<0.0001
≥3.2	5959	1.12 (1.10, 1.14)	<0.0001
Bicarbonate (mmol/L)				0.0004
<24	5009	1.12 (1.10, 1.13)	<0.0001
≥24	6564	1.07 (1.05, 1.09)	<0.0001
Bilirubin (mg/dL)				<0.0001
<0.7	4674	1.07 (1.05, 1.09)	<0.0001
≥0.7	5521	1.13 (1.12, 1.14)	<0.0001
Sodium (mmol/L)				0.0608
<140	4737	1.12 (1.10, 1.13)	<0.0001
≥140	6836	1.11 (1.09, 1.12)	<0.0001
Potassium (mmol/L)				0.4309
<4.6	5580	1.10 (1.09, 1.12)	<0.0001
≥4.6	5993	1.11 (1.10, 1.12)	<0.0001
Lactate (mmol/L)				<0.0001
<2.5	4334	1.06 (1.03, 1.08)	<0.0001
≥2.5	4416	1.12 (1.11, 1.14)	<0.0001
BUN (mg/dL)				0.0610
<30	5689	1.12 (1.10, 1.15)	<0.0001
≥30	5884	1.09 (1.08, 1.10)	<0.0001
PT (seconds)				<0.0001
<15.2	5464	1.07 (1.05, 1.09)	<0.0001
≥15.2	5602	1.12 (1.11, 1.13)	<0.0001
INR				<0.0001
<1.4	4976	1.07 (1.04, 1.09)	<0.0001
≥1.4	6088	1.11 (1.10, 1.13)	<0.0001
APTT (seconds)				<0.0001
<34.8	5501	1.07 (1.05, 1.09)	<0.0001
≥34.8	5544	1.12 (1.11, 1.13)	<0.0001
WBC (10⁹/L)				0.0245
<13	5755	1.10 (1.09, 1.12)	<0.0001
≥13	5808	1.11 (1.10, 1.12)	<0.0001
Platelet (10⁹/L)				0.0888
<226	5758	1.12 (1.11, 1.13)	<0.0001
≥226	5805	1.10 (1.08, 1.12)	<0.0001
Hematocrit (%)				<0.0001
<34.9	5770	1.08 (1.07, 1.10)	<0.0001
≥34.9	5796	1.15 (1.13, 1.17)	<0.0001
Hemoglobin (g/dL)				<0.0001
<11.6	5699	1.09 (1.07, 1.10)	<0.0001
≥11.6	5860	1.14 (1.13, 1.16)	<0.0001
Creatinine (mEq/L)				<0.0001
<1.4	5416	1.06 (1.04, 1.09)	<0.0001
≥1.4	6157	1.11 (1.10, 1.13)	<0.0001
Glucose (mg/dL)				0.3993
<165	5744	1.11 (1.09, 1.13)	<0.0001
≥165	5828	1.11 (1.10, 1.13)	<0.0001
Chloride (mmol/L)				0.0067
<107	5118	1.10 (1.09, 1.12)	<0.0001
≥107	6455	1.13 (1.11, 1.15)	<0.0001
SBP (mmHg)				<0.0001
<114	5763	1.13 (1.11, 1.14)	<0.0001
≥114	5777	1.08 (1.06, 1.09)	<0.0001
DBP (mmHg)				0.0099
<60	5761	1.12 (1.11, 1.14)	<0.0001
≥60	5779	1.09 (1.08, 1.11)	<0.0001
MBP (mmHg)				0.0004
<76	5765	1.12 (1.11, 1.14)	<0.0001
≥76	5782	1.09 (1.07, 1.11)	<0.0001
Heart rate (beats/minute)				0.5626
<87	5767	1.11 (1.09, 1.13)	<0.0001
≥87	5781	1.11 (1.10, 1.13)	<0.0001
Respiratory rate (beats/minute)				0.4296
<19	5760	1.10 (1.08, 1.12)	<0.0001
≥19	5777	1.11 (1.09, 1.12)	<0.0001
Temperature (°C)				0.0080
<36.8	5717	1.10 (1.09, 1.11)	<0.0001
≥36.8	5725	1.12 (1.10, 1.14)	<0.0001
SPO2 (%)				0.3747
<97	5779	1.12 (1.10, 1.13)	<0.0001
≥97	5765	1.11 (1.09, 1.12)	<0.0001
SOFA score				0.0513
<5	4872	1.08 (1.05, 1.11)	<0.0001
≥5	6701	1.09 (1.08, 1.10)	<0.0001
SAPSII score				0.0306
<39	5479	1.08 (1.05, 1.11)	<0.0001
≥39	6094	1.08 (1.07, 1.09)	<0.0001
RRT				<0.0001
No	10090	1.12 (1.11, 1.14)	<0.0001
Yes	1483	1.06 (1.04, 1.08)	<0.0001

CHF: congestive heart failure; CAD: coronary artery disease; AFIB: atrial fibrillation; ARDS: acute respiratory distress syndrome; AKI: acute kidney injury; BUN: blood urea nitrogen; PT: prothrombin time; INR: international normalized ratio; APTT: activated partial thromboplastin time; WBC: white blood cell; SBP: systolic blood pressure; DBP: diastolic blood pressure; MBP: mean blood pressure; SOFA: sequential organ failure assessment; SAPSII: simplified acute physiology score II; RRT: renal replacement therapy.