Table 1 Comparison of baseline demographic, clinical, and laboratory characteristics between the antibiotic and no-antibiotic groups

Age,years

50.1 ± 16.2

50.5 ± 16.4

49.5 ± 16.0

0.247

Male,n(%)

747(65.8)

447(65.6)

300(66.2)

0.445

BMI Index (kg/m²)

25.6 ± 4.3

25.6 ± 4.4

25.2 ± 4.1

0.548

Etiology

 Biliary,n(%)

654(57.6)

388(59.3)

266(40.7)

0.560

 Hyperlipidemic,n(%)

353(31.1)

211(59.8)

142(40.2)

0.897

 Alcoholic,n(%)

71(6.2)

37(52.1)

34(47.9)

0.158

 Other,n(%)

56(4.9)

45(52.1)

11(19.6)

0.200

Severity Grade

 Mild,n(%)

459(40.4)

132(19.3)

327(72.1)

< 0.001^*

 Moderate-severe,n(%)

429(37.8)

322(47.2)

107(23.6)

< 0.001^*

 Severe,n(%)

246(21.6)

227(33.3)

19(2.4)

< 0.001^*

Comorbidity

 HBP,n(%)

383(33.7)

230(60.1)

153(39.9)

0.492

 DM,n(%)

224(19.7)

148(66.1)

76(33.9)

0.023^*

Smoking,n(%)

355(31.2)

229(33.6)

126(66.4)

0.220

Drinking,n(%)

352(31.0)

216(61.4)

136(38.6)

0.295

Laboratory indicators on admission

 Leukocyte count(×10⁹/L)

14.2 ± 5.3

14.7 ± 5.3

13.3 ± 5.1

0.338

 Pct(ng/ml)

3.6 ± 9.2

4.7 ± 10.8

1.1 ± 2.6

< 0.001^*

 CRP(μg/ml)

140.0 ± 117.9

144.2 ± 125.2

89.4 ± 102.4

< 0.001^*

 Platelet count(×10⁹/L)

204.0 ± 67.3

206.9 ± 65.3

203.9 ± 68.8

0.560

 Serum amylase(U/L)

866.0 ± 1158.0

954.6 ± 1316.8

693.0 ± 827.3

0.003^*

 Alanine aminotransferase(U/L)

71.7 ± 110.0

73.4 ± 114.0

69.3 ± 106.0

0.341

 Total bilirubin(μmol/L)

29.0 ± 32.3

30.4 ± 36.8

26.8 ± 24.1

0.021^*

 Creatinine(μmol/L)

85.1 ± 67.0

92.7 ± 79.2

73.4 ± 40.0

< 0.001^*

 Calcium(mmol/L)

2.1 ± 5.2

2.2 ± 6.8

2.0 ± 0.1

0.203

 Glucose(mmol/L)

9.3 ± 4.7

9.1 ± 4.8

9.1 ± 4.8

0.945

 Potassium(mmol/L)

3.8 ± 0.6

3.9 ± 0.6

3.8 ± 0.5

0.469

 Triglycerides(mmol/L)

7.2 ± 13.4

8.3 ± 15.3

5.4 ± 9.3

< 0.001^*

Modified Marshall score

0(0–8)

0(0–6)

0(0–8)

0.469

BISAP score

1(0–6)

2(0–5)

0(0–4)

< 0.001^*

APACHE II score

5(0–29)

7(0–29)

5(0–29)

0.348

CTSI score

4(0–8)

4(0–8)

3(0–8)

< 0.001^*

Laparotomy,n(%)

47(4.1)

36(5.3)

11(2.4)

0.012^*

Length of hospital stay,(days)

24.8 ± 23.5

28.9 ± 24.5

29.4 ± 26.1

0.753

In-hospital mortality,n(%)

34(2.99)

28(4.1)

6(1.3)

0.735