Table 1 Baseline characteristics of patients with VAP

Age, year, Mean ± SD

61.61 ± 16.19

60.01 ± 16.40

68.39 ± 13.27

<0.001

Gender, n (%)

0.690

 Female

567 (36.75)

456 (36.51)

111 (37.76)

 Male

976 (63.25)

793 (63.49)

183 (62.24)

Ethnicity, n (%)

0.024

 White

892 (57.81)

733 (58.69)

159 (54.08)

 Black

168 (10.89)

143 (11.45)

25 (8.50)

 Other

177 (11.47)

143 (11.45)

34 (11.56)

 Unknown

306 (19.83)

230 (18.41)

76 (25.85)

Insurance, n (%)

0.019

 Medicaid

143 (9.27)

120 (9.61)

23 (7.82)

 Medicare

664 (43.03)

516 (41.31)

148 (50.34)

 Other

736 (47.70)

613 (49.08)

123 (41.84)

Marital status, n (%)

<0.001

 Divorced

123 (7.97)

88 (7.05)

35 (11.90)

 Married

758 (49.13)

604 (48.36)

154 (52.38)

 Single

505 (32.73)

437 (34.99)

68 (23.13)

 Widowed

157 (10.17)

120 (9.61)

37 (12.59)

Weight, kg, Mean ± SD

85.16 ± 26.67

85.69 ± 27.11

82.92 ± 24.62

0.089

Heart rate, bpm, Mean ± SD

90.71 ± 21.48

90.82 ± 21.40

90.23 ± 21.86

0.677

SBP, mmHg, Mean ± SD

124.70 ± 26.60

125.02 ± 26.41

123.35 ± 27.41

0.332

DBP, mmHg, Mean ± SD

69.08 ± 18.49

69.61 ± 18.49

66.81 ± 18.32

0.019

Respiratory rate, bpm, Mean ± SD

19.88 ± 6.12

19.78 ± 6.14

20.28 ± 6.02

0.212

Temperature, ℃, Mean ± SD

36.74 ± 1.01

36.77 ± 0.99

36.58 ± 1.07

0.004

WBC, K/uL, M (Q₁, Q₃)

11.90 (8.70, 16.30)

11.90 (8.70, 16.10)

12.20 (9.10, 17.50)

0.155

PLT, K/uL, M (Q₁, Q₃)

193.00 (135.00, 254.00)

194.00 (135.00, 254.00)

187.50 (135.00, 257.00)

0.989

Hemoglobin, g/dL, Mean ± SD

10.90 ± 2.43

10.98 ± 2.43

10.57 ± 2.42

0.010

RDW, %, Mean ± SD

15.16 ± 2.33

15.06 ± 2.29

15.59 ± 2.46

<0.001

Creatinine, mg/dL, M (Q₁, Q₃)

1.00 (0.80, 1.60)

1.00 (0.70, 1.60)

1.30 (0.80, 1.90)

<0.001

INR, ratio, M (Q₁, Q₃)

1.20 (1.10, 1.50)

1.20 (1.10, 1.50)

1.30 (1.10, 1.70)

0.008

BUN, mg/dL, M (Q₁, Q₃)

21.00 (14.00, 34.00)

20.00 (13.00, 31.00)

26.00 (17.00, 45.00)

<0.001

Glucose, mg/dL, M (Q₁, Q₃)

139.00 (111.00, 181.00)

139.00 (111.00, 181.00)

138.50 (112.00, 187.00)

0.535

SPO2, %, Mean ± SD

96.92 ± 4.56

96.97 ± 4.57

96.68 ± 4.49

0.314

Anion gap, mEq/L, Mean ± SD

15.43 ± 4.82

15.25 ± 4.76

16.20 ± 5.01

0.002

Congestive heart failure (Yes), n (%)

502 (32.53)

374 (29.94)

128 (43.54)

<0.001

Sepsis (Yes), n (%)

1248 (80.88)

1003 (80.30)

245 (83.33)

0.235

Respiratory failure (Yes), n (%)

851 (55.15)

664 (53.16)

187 (63.61)

0.001

GCS, score, M (Q₁, Q₃)

8.00 (4.00, 12.00)

8.00 (5.00, 12.00)

7.00 (3.00, 11.00)

<0.001

CCI, score, M (Q₁, Q₃)

3.00 (1.00, 4.00)

2.00 (1.00, 4.00)

4.00 (2.00, 5.00)

<0.001

SOFA, score, M (Q₁, Q₃)

8.00 (5.00, 11.00)

8.00 (5.00, 11.00)

9.00 (6.00, 12.00)

<0.001

SAPSII, score, M (Q₁, Q₃)

40.00 (31.00, 50.00)

38.00 (30.00, 48.00)

46.00 (37.00, 56.00)

<0.001

Vasopressors (Yes), n (%)

1044 (67.66)

818 (65.49)

226 (76.87)

<0.001

RRT (Yes), n (%)

293 (18.99)

210 (16.81)

83 (28.23)

<0.001

Thiamine (Yes), n (%)

254 (16.46)

214 (17.13)

40 (13.61)

0.142

Antibiotics use

 Vancomycin (Yes), n (%)

1382 (89.57)

1114 (89.19)

268 (91.16)

0.321

 Cephalosporins (Yes), n (%)

1228 (79.59)

994 (79.58)

234 (79.59)

0.998

 Penicillin (Yes), n (%)

721 (46.73)

598 (47.88)

123 (41.84)

0.062

 Aminoglycoside (Yes), n (%)

207 (13.42)

174 (13.93)

33 (11.22)

0.221

 Others, n (%)

1055 (68.37)

849 (67.97)

206 (70.07)

0.487

Pathogen

 Gram-negative bacteria

  Escherichia coli (Yes), n (%)

185 (11.99)

154 (12.33)

31 (10.54)

0.396

  Klebsiella pneumoniae (Yes), n (%)

172 (11.15)

138 (11.05)

34 (11.56)

0.800

  Pseudomonas aeruginosa (Yes), n (%)

224 (14.52)

188 (15.05)

36 (12.24)

0.219

  Serratia marcescens (Yes), n (%)

61 (3.95)

49 (3.92)

12 (4.08)

0.900

  Proteus (Yes), n (%)

50 (3.24)

42 (3.36)

8 (2.72)

0.576

  Acinetobacter (Yes), n (%)

53 (3.43)

38 (3.04)

15 (5.10)

0.081

  Haemophilus influenzae (Yes), n (%)

115 (7.45)

97 (7.77)

18 (6.12)

0.334

 Gram-positive bacteria

  Methicillin resistant staph aureus (Yes), n (%)

102 (6.61)

78 (6.24)

24 (8.16)

0.234

  Staph aureus coag + (Yes), n (%)

477 (30.91)

389 (31.14)

88 (29.93)

0.686

  Streptococcus pneumoniae (Yes), n (%)

37 (2.40)

30 (2.40)

7 (2.38)

0.983

Fungus (Yes), n (%)

133 (8.62)

101 (8.09)

32 (10.88)

0.124

Duration of mechanical ventilation, hour, M (Q₁, Q₃)

151.53 (76.00, 268.27)

153.00 (78.00, 278.50)

146.38 (67.18, 233.50)

0.014

Follow-up, day, M (Q₁, Q₃)

30.00 (30.00, 30.00)

30.00 (30.00, 30.00)

13.27 (9.14, 18.55)

<0.001