|
Risk Factor
|
Odds Ratio
|
95% Confidence Interval
|
|
mechanical ventilation
|
9.8
|
2.7 to 35.6
|
|
upper abdominal surgery
|
4.7
|
1.6 to 13.9
|
|
chronic lung disease
|
5.9
|
1.7 to 21.2
|
|
NNIS index
|
2.2 for each point (2.2, 4.4, 6.6)
|
1.1 to 4.4 per point
|
|
obesity
|
2.9
|
0.9 to 9.4
|
see Summary and Table IV page 274
where:
• NNIS index = National Nosocomial Infection Surveillance index, with values ranging from 0 to 3. This is described below in the section on surgical site infections.
• The SENIC index was also evaluated, but the NNIS index was felt to be the better indicator.
• Obesity is defined as a body mass index (BMI) > 90th percentile. For the Spanish population this would be > 33.75.
number of risk factors present =
= SUM(number of factors present)
Interpretation:
• minimum number of risk factors: 0
• maximum number of risk factors: 5
• The risk of postoperative infection increases with the number of risk factors present.
NOTE: The authors did not offer a risk score to correlate with the incidence of postoperative pneumonia. In the implementation I kluged a simple score that has not been tested clinically, with 1 point assigned for each 2.2 odds ratio.
