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. 2021 Aug 5;14:4183–4195. doi: 10.2147/IJGM.S321581

Table 3.

Subgroup Analysis of the Associations Between Serum HCO3− and 30-Day All-Cause Mortality

No. of Patients Serum HCO3− Levels (mmol/L) P for Interaction
<22 22–24 >24
Gender 0.828
 Male 213 2.96 (1.29, 6.80) ref 0.66 (0.23, 1.89)
 Female 123 3.25 (1.00, 10.56) ref 1.09 (0.27, 4.38)
Age, years 0.924
 <69 165 3.18 (1.26, 8.01) ref 0.92 (0.30, 2.85)
 ≥69 171 2.66 (0.95, 7.48) ref 0.651 (0.18, 2.31)
Insurance /
 Government 20 / ref /
 Medicaid 17 / ref /
 Medicare 176 2.32 (0.90, 5.99) ref 0.39 (0.10, 1.53)
 Private 118 3.66 (1.32, 10.16) ref 0.91 (0.24, 3.37)
 Selfpay 5 / ref 1.00 (1.00, 1.00)
Ethnicity 0.89
 White 233 3.18 (1.38, 7.33) ref 0.87 (0.30, 2.49)
 Black 44 1.38 (0.28, 6.84) ref 0.49 (0.08, 2.94)
 Hispanic 13 / ref /
 Others 46 5.88 (0.69, 50.40) ref 0.91 (0.08, 10.01)
Stanford type 0.387
 A type 230 8.50 (1.05, 16.26) ref 0.95 (0.06, 16.29)
 B type 106 2.27 (1.17, 5.94) ref 0.65 (0.20, 2.09)
Aorta replacement 0.768
 No 138 5.27 (1.44, 8.94) ref 0.64 (0.72, 3.16)
 Yes 198 2.75 (0.98, 7.13) ref 0.54 (0.17, 2.83)
ICU MV 0.753
 No 166 3.57 (2.26, 5.23) ref 0.79 (0.33, 2.54)
 Yes 170 4.92 (1.67, 9.91) ref 0.88 (0.12, 4.58)
Hypertension 0.179
 No 137 1.77 (0.72, 4.35) ref 0.32 (0.08, 1.22)
 Yes 199 4.64 (1.63, 13.17) ref 1.53 (0.48, 4.81)
Diabetes 0.091
 No 306 2.572 (1.27, 5.20) ref 0.78 (0.34, 1.81)
 Yes 30 / ref /
Hypercholesterolemia 0.156
 No 283 3.56 (1.64, 7.69) ref 1.04 (0.42, 2.55)
 Yes 53 1.597 (0.36, 7.14) ref /
Valvular disease 0.668
 No 303 3.00 (1.42, 6.33) ref 0.87 (0.36, 2.15)
 Yes 33 3.36 (0.65, 17.39) ref 0.38 (0.03, 4.19)
Malignancy 0.478
 No 325 2.93 (1.48, 5.81) ref 0.79 (0.34, 1.83)
 Yes 11 / ref /
Stroke 0.891
 No 310 3.22 (1.47, 7.02) ref 0.85 (0.33, 2.21)
 Yes 26 2.27 (0.56, 9.18) ref 0.54 (0.09, 3.23)
CAD 0.16
 No 276 4.25 (1.88, 9.59) ref 1.09 (0.42, 2.81)
 Yes 60 1.00 (0.28, 3.54) ref 0.21 (0.02, 1.90)
CHF 0.307
 No 305 3.29 (1.57, 6.88) ref 0.94 (0.39, 2.25)
 Yes 31 1.91 (0.32, 11.43) ref /
Atrial fibrillation 0.735
 No 279 3.49 (1.62, 7.55) ref 0.84 (0.32, 2.18)
 Yes 57 1.80 (0.40, 8.03) ref 0.64 (0.11, 3.83)
Renal disease 0.094
 No 291 3.16 (1.44, 6.94) ref 1.07 (0.43, 2.62)
 Yes 45 2.35 (0.61, 9.13) ref /
Liver disease 0.049
 No 326 2.77 (1.39, 5.51) ref 0.79 (0.34, 1.83)
 Yes 10 / ref /
Respiratory disease 0.727
 No 272 3.51 (1.55, 7.92) ref 0.87 (0.30, 2.50)
 Yes 64 2.21 (0.62, 7.86) ref 0.42 (0.11, 1.69)
AKI 0.507
 No 201 3.10 (1.22, 7.87) ref 1.06 (0.39, 2.93)
 Yes 135 2.83 (1.03, 7.80) ref 0.40 (0.08, 2.03)
RRT 0.418
 No 307 2.94 (1.43, 6.06) ref 0.86 (0.37, 2.03)
 Yes 29 3.31 (0.39, 28.38) ref /
WBC, 103/µL 0.84
 <8.8 167 2.47 (0.85, 7.26) ref 0.63 (0.17, 2.35)
 ≥8.8 169 3.58 (1.49, 8.64) ref 0.99 (0.33, 2.94)
RDW, % 0.873
 <14.4 159 3.58 (1.26, 10.17) ref 0.84 (0.23, 3.12)
 ≥14.4 177 2.65 (1.08, 6.50) ref 0.74 (0.25, 2.22)
Hematocrit, % 0.985
 <28.9 167 2.91 (1.21, 7.01) ref 0.80 (0.25, 2.51)
 ≥28.9 169 3.16 (1.08, 9.26) ref 0.83 (0.24, 2.85)
Hb, g/dL 0.895
 <9.7 163 2.75 (1.15, 6.60) ref 0.65 (0.19, 2.23)
 ≥9.7 173 3.25 (1.09, 9.71) ref 0.99 (0.30, 3.23)
RBC, 103/µL 0.254
 <3.66 167 5.46 (1.9, 16.06) ref 1.30 (0.33, 5.21)
 ≥3.66 169 1.67 (0.63, 4.46) ref 0.55 (0.19, 1.58)
Platelet, 103/µL 0.561
 <164 165 4.06 (1.50, 11.00) ref 1.29 (0.37, 4.45)
 ≥164 171 2.29 (0.87, 6.03) ref 0.53 (0.17, 1.67)
Anion gap, mmol/L 0.313
 <12 126 1.42 (0.41, 4.91) ref 0.63 (0.18, 2.18)
 ≥12 210 4.18 (1.79, 9.80) ref 0.89 (0.28, 2.81)
pH value 0.072
 <7.39 167 6.19 (2.15, 10.74) ref 0.68 (0.58, 3.20)
 ≥7.39 169 2.63 (1.39, 6.18) ref 0.87 (0.31, 2.01)
Lactate, mmol/L 0.311
 <4.1 166 5.13 (1.27, 8.84) ref 1.12 (0.32, 3.84)
 ≥4.1 170 3.11 (1.33, 5.26) ref 0.91 (0.33, 2.50)
BUN, mg/dL 0.979
 <16 153 3.19 (0.80, 12.74) ref 0.92 (0.19, 4.57)
 ≥16 183 2.83 (1.29, 6.18) ref 0.76 (0.28, 2.04)
Creatinine, mg/dL 0.735
 <1 132 4.12 (1.24, 13.70) ref 1.12 (0.32, 3.95)
 ≥1 204 2.65 (1.16, 6.04) ref 0.58 (0.17, 1.91)
Chloride, mmol/L 0.719
 <103 167 2.36 (0.90, 6.19) ref 0.69 (0.24, 1.97)
 ≥103 169 4.00 (1.47, 10.84) ref 0.82 (0.20, 3.45)
Glucose, mg/dL 0.876
 <103 167 3.29 (1.05, 10.34) ref 0.65 (0.15, 2.90)
 ≥103 169 3.10 (1.33, 7.26) ref 0.91 (0.33, 2.50)
APTT, s 0.59
 <28.1 167 2.82 (1.11, 7.16) ref 1.03 (0.35, 3.06)
 ≥28.1 169 3.33 (1.21, 9.17) ref 0.60 (0.16, 2.22)
INR 0.628
 <1.2 152 3.61 (1.39, 9.41) ref 0.63 (0.18, 2.22)
 ≥1.2 184 2.69 (1.02, 7.06) ref 0.96 (0.31, 2.96)
PT, s 0.775
 <13.4 165 3.19 (1.21, 8.40) ref 0.62 (0.18, 2.20)
 ≥13.4 171 2.96 (1.14, 7.69) ref 0.97 (0.31, 3.01)
Sodium, mmol/L 0.831
 <137 166 3.22 (1.26, 8.23) ref 1.03 (0.32, 3.38)
 ≥137 170 2.92 (1.08, 7.91) ref 0.63 (0.19, 2.08)
Potassium, mmol/L 0.726
 <3.6 143 4.40 (1.23, 15.77) ref 0.81 (0.16, 4.03)
 ≥3.6 193 2.65 (1.17, 6.00) ref 0.83 (0.31, 2.22)
Total calcium, mg/dL 0.332
 <8.5 152 6.16 (1.75, 21.63) ref 1.46 (0.33, 6.51)
 ≥8.5 184 2.06 (0.89, 4.756) ref 0.57 (0.20, 1.59)
Magnesium, mg/dL 0.521
 <2 119 2.20 (0.82, 5.91) ref 0.48 (0.12, 1.84)
 ≥2 217 4.32 (1.60, 11.64) ref 1.21 (0.38, 3.82)
SBP, mmHg 0.728
 <151 166 3.27 (1.17, 9.18) ref 1.09 (0.33, 3.57)
 ≥151 170 2.96 (1.19, 7.32) ref 0.56 (0.17, 1.93)
DBP, mmHg 0.561
 <81 162 2.92 (1.00, 8.55) ref 1.13 (0.34, 3.69)
 ≥81 174 3.10 (1.28, 7.48) ref 0.55 (0.16, 1.87)
MBP, mmHg 0.102
 <102 162 2.57 (0.79, 8.35) ref 1.46 (0.43, 4.98)
 ≥102 174 3.62 (1.57, 8.34) ref 0.40 (0.11, 1.50)
HR, beats/min 0.914
 <90 162 3.59 (1.12, 11.44) ref 0.83 (0.21, 3.30)
 ≥90 174 2.76 (1.19, 6.40) ref 0.82 (0.29, 2.37)
RR, times/min 0.599
 <25 155 3.17 (0.79, 12.68) ref 0.35 (0.04, 3.40)
 ≥25 181 2.76 (1.26, 6.03) ref 0.86 (0.34, 2.15)
Temperature, °C 0.293
 <37.28 166 2.22 (0.97, 5.07) ref 0.79 (0.30, 2.04)
 ≥37.28 170 5.59 (1.58, 19.82) ref 0.67 (0.11, 4.03)
SPO2, % 0.853
 <92 135 2.41 (0.98, 5.92) ref 0.65 (0.22, 1.93)
 ≥92 201 3.63 (1.28, 10.31) ref 0.87 (0.23, 3.24)