Table 2 Multivariate analysis of cause-specific hazard ratios for the acquisition of nosocomial pneumonia (model 1)

Baseline:

Age (continuous variable)

1.01

1.00 to 1.02

0.18

1.00

1.00 to 1.01

0.01

Female gender

0.75

0.53 to 1.07

0.12

1.10

0.99 to 1.22

0.07

SAPS II (continuous variable)

1.00

0.98 to 1.01

0.42

0.98

0.98 to 0.99

< 0.01

Intubation on admission

0.89

0.71 to 1.13

0.35

1.05

0.96 to 1.14

0.32

Pneumonia on admission

0.02

0.00 to 0.12

< 0.01

0.66

0.56 to 0.77

< 0.01

Urinary tract infection on admission

1.86

0.60 to 5.82

0.28

0.81

0.56 to 1.18

0.28

Other infections on admission

1.08

0.59 to 1.98

0.79

0.72

0.59 to 0.89

< 0.01

Hospitalization before admission

0.73

0.50 to 1.05

0.09

0.91

0.81 to 1.02

0.10

Surgical patients

0.69

0.41 to 1.18

0.18

0.98

0.83 to 1.16

0.80

Elective surgery before admission

1.95

1.33 to 2.85

< 0.01

0.54

0.48 to 0.60

< 0.01

Emergency surgery before admission

1.59

1.10 to 2.28

0.01

1.08

0.95 to 1.23

0.25

Cardial/pulmonary underlying disease

1.32

0.86 to 2.04

0.20

0.84

0.73 to 0.97

0.02

Neurological underlying disease

1.25

0.78 to 2.00

0.36

0.94

0.81 to 1.09

0.41

Metabolic/renal underlying disease

0.76

0.35 to 1.65

0.48

0.80

0.65 to 0.99

0.04

Other underlying disease

1.49

0.83 to 2.66

0.18

1.00

0.81 to 1.24

1.00

Time-dependent:

Ventilation

5.90

2.47 to 14.09

< 0.01

0.53

0.45 to 0.62

< 0.01

Chest drainage

1.00

0.68 to 1.46

0.99

0.75

0.65 to 0.86

< 0.01

Colostomy

4.29

0.36 to 50.64

0.25

0.69

0.28 to 1.72

0.42

Enterostomy

0.14

0.01 to 2.10

0.15

1.64

0.61 to 4.45

0.33

Jejunostomy

2.47

0.45 to 13.58

0.30

0.41

0.16 to 1.04

0.06

Nasogastric tube

3.04

1.25 to 7.37

0.01

0.89

0.76 to 1.03

0.12

Urinary catheter

1.53

0.49 to 4.81

0.46

0.76

0.65 to 0.90

< 0.01