Patient selection: variceal bleeding in a patient with cirrhosis
Outcome: 6-week mortality for bleeding from varices
Parameters:
(1) serum albumin in g/dL
(2) encephalopathy
(3) serum total bilirubin in mg/dL
(4) hepatocellular carcinoma
(5) total number of blood units transfused
|
Parameter
|
Finding
|
Points
|
|
encephalopathy
|
none
|
1
|
|
|
mild
|
2
|
|
|
severe
|
3
|
|
hepatocellular carcinoma
|
no
|
0
|
|
|
yes
|
1
|
X for model 1 =
= (0.88 * (points for encephalopathy)) + (0.22 * (serum total bilirubin)) + (1.12 * (points for hepatocellular carcinoma)) - (0.86 * (serum albumin)) - 0.083
probability of mortality by model 1 =
= 1 / (1 + EXP((-1) * X))
Y for model 2 =
= (0.83 * (points for encephalopathy)) + (0.21 * (serum total bilirubin)) + (1.24 * (points for hepatocellular carcinoma)) - (0.83 * (serum albumin)) + (0.34 * (number of units)) - 0.84
probability of mortality by model 2 =
= 1 / (1 + EXP((-1) * Y))
Performance:
• The area under the ROC curve is 0.79 for model 1 and 0.83 for model 2.
