Table 3

Risk factors for ventilator-associated pneumonia: crude and adjusted effect of staffing level

Risk factor
Early-onset VAP
Late-onset VAP



Crude HR (95% CI)
Adjusted HR (95% CI)
Crude HR (95% CI)
Adjusted HR (95% CI)

Nurse-to-patient ratio
0.77 (0.42 to 1.40)
0.78 (0.42 to 1.45)
0.43 (0.18 to 1.02)
0.42 (0.18 to 0.99)
Patient age
1.00 (0.99 to 1.01)
-
1.00 (0.99 to 1.01)
-
Male gender
0.92 (0.62 to 1.38)
-
1.15 (0.79 to 1.69)
-
Nursing acuity severity score
0.96 (0.92 to 1.01)
-
1.03 (1.00 to 1.07)
1.04 (1.00 to 1.08)
Charlson score
0.89 (0.81 to 0.99)
0.89 (0.80 to 0.98)
0.96 (0.87 to 1.05)

Admission diagnosis




     Infectious disease
0.75 (0.46 to 1.20)
-
1.09 (0.75 to 1.60)
-
     Cardiovascular condition
1.63 (1.10 to 2.41)
-
1.47 (0.97 to 2.23)
-
     Pulmonary disease
0.77 (0.44 to 1.33)
-
0.56 (0.31 to 1.02)
0.53 (0.29 to 0.97)
     Other
0.87 (0.53 to 1.41)
-
0.84 (0.49 to 1.43)
-
APACHE II score




     < 26
1
-
1
-
     26 to 30
1.12 (0.67 to 1.86)
-
0.92 (0.49 to 1.72)
-
     > 30
0.83 (0.53 to 1.31)
-
1.08 (0.70 to 1.67)
-
Nursing training levela
0.84 (0.60 to 1.18)
-
1.19 (0.91 to 1.56)
-
Invasive devices




     Central vascular line
1.50 (0.92 to 2.45)
1.71 (1.05 to 2.81)
3.06 (0.97 to 9.70)
4.14 (1.26 to 13.55)
     Peripheral venous line
2.06 (0.76 to 5.61)
-
1.47 (0.95 to 2.29)
1.65 (1.06 to 2.59)
     Peripheral arterial line
0.58 (0.32 to 1.06)
-
5.65 (0.78 to 40.84)
-
     Urinary catheter
1.86 (0.66 to 5.26)
-
1.31 (0.41 to 4.16)
-
     Nasogastric tube
1.40 (0.75 to 2.63)
-
2.39 (0.76 to 7.54)
-
Medication




     Parenteral nutrition
0.83 (0.49 to 1.41)
-
0.99 (0.65 to 1.51)
-
     Therapeutic antibiotic
0.48 (0.32 to 0.73)
0.47 (0.31 to 0.71)
0.51 (0.29 to 0.91)
0.34 (0.19 to 0.62)
     Prophylactic antibiotic
0.58 (0.18 to 1.84)
-
1.22 (0.56 to 2.63)
-
     Gastric antacid drug
1.34 (0.90 to 2.00)
-
0.98 (0.66 to 1.46)
-

aNursing training level is the number of intensive care unit certified nurses divided by the number of trainee nurses in critical care. APACHE, Acute Physiology and Chronic Health Evaluation; CI, confidence intervals; HR, hazard ratio; VAP, ventilator-associated pneumonia.

Hugonnet et al. Critical Care 2007 11:R80   doi:10.1186/cc5974