Patient selection: surgical patient, status post hepatectomy
Parameters:
(1) splenomegaly
(2) blood transfusion
(3) admission to the ICU (timing relative to surgery not stated)
(4) postoperative serum albumin concentration in g/L
|
Parameter
|
Finding
|
Beta-Coefficient
|
Points
|
|
splenomegaly
|
absent
|
0
|
0
|
|
|
present
|
1.57
|
1.6
|
|
blood transfusion
|
no
|
0
|
0
|
|
|
yes
|
1.13
|
1
|
|
admission to ICU
|
no
|
0
|
0
|
|
|
yes
|
1
|
1
|
|
postop albumin
|
|
1.16 * (albumin)
|
NA
|
|
|
<= 35 g/L
|
NA
|
1
|
|
|
> 35 g/L
|
NA
|
0
|
where:
• The paper references serum albumin g/L, but the logistic regression model fails if this is used. Also the risk given by the score rises with a higher serum albumin which is opposite to the simple point score and the data shown in Table 1.
simple score =
= SUM(points for all 4 parameters)
value of X =
= SUM(beta-coefficients for all 4 parameters) - 3.70
probability of a superficial SSI =
= 1 / (1 + EXP((-1) * X))
Interpretation:
• minimum score: 0
• maximum score: 4.6
|
Simple Score
|
Risk for Superficial SSI
|
Percent with SSI
|
|
< 1
|
low
|
13%
|
|
1 to 2
|
moderate
|
36%
|
|
> 2
|
high
|
52%
|
Performance of the simple score:
• The area under the ROC curve is 0.70.
