Table 2 Distribution of cases and controls according to their demographic and clinical characteristics: results of univariate analysis

 Male

32 (47.8)

64 (47.8)

1.00

  ≤ 40

2 (2.9)

5 (3.7)

0.786

 41–64

32 (47.8)

58 (43.3)

0.547

  ≥ 65 years

33 (49.2)

71 (52.9)

0.618

  Diabetes mellitus

10 (14.9)

15 (11.2)

0.451

 Malignacy

14 (20.9)

22 (16.4)

0.436

 Previous hospitalization

13 (19.4)

19 (14.1)

0.342

 ICU admission

22 (32.8)

19 (14.1)

0.003

  ≥ 5 days in ICU

67 (100.0)

121 (90.3)

0.051

 Nasogastric tube

5 (7.4)

1 (0.7)

0.032

 Mechanical ventilation

4 (5.9)

0 (0.0)

0.032

 Proton-pump inhibitors

13 (19.4)

8 (5.9)

0.005

 H2 receptor antagonist

40 (59.7)

62 (46.2)

0.074

 Corticosteroides

4 (5.9)

1 (0.7)

0.059

 One antibiotic

32 (47.8)

85 (63.4)

0.035

 Days of usage an antibiotic

5.13 ± 2.14

4.40 ± 2.27

0.120

 Two antibiotics

20 (29.9)

27 (20.1)

0.128

 Days of usage two antibiotics

5.85 ± 3.79

4.63 ± 2.13

0.167

 Three antibiotics

9 (13.4)

5 (3.7)

0.017

 Days of usage three antibiotics

7.89 ± 5.89

5.60 ± 2.07

0.423

 Four antibiotics

4 (6.0)

2 (1.5)

0.103

 Days of usage four antibiotics

8.75 ± 4.35

7.00 ± 2.83

0.642

 Cephalosporins 1st gen.

15 (22.4)

33 (24.6)

0.726

 Days of usage cephalosporins 1st gen.

1.15 ± 2.47

1.04 ± 2.16

0.742

 Cephalosporins 2nd gen.

14 (20.9)

25 (18.7)

0.705

 Days of usage cephalosporins 2nd gen.

1.18 ± 2.50

0.96 ± 2.25

0.537

 Cephalosporins 3rd gen.

42 (62.7)

62 (46.3)

0.029

 Days of usage cephalosporins 3rd gen.

4.39 ± 4.59

2.51 ± 3.25

0.001

 Aminiglycosides

7 (10.4)

18 (13.4)

0.546

 Days of usage Aminoglycosides

0.91 ± 3.58

0.66 ± 2.10

0.528

 Quinolones

6 (8.9)

4 (3.0)

0.080

 Days of usage Quinolones

0.52 ± 1.76

0.16 ± 0.94

0.056

 Sulfonamides

3 (4.5)

5 (3.7)

0.799

 Days of usage Sulfonamides

0.25 ± 1.26

0.15 ± 0.86

0.491

 Carbapenems

6 (9.0)

2 (1.5)

0.024

 Days of usage Carbapenems

0.62 ± 2.10

0.10 ± 0.85

0.014