Parameters identified on multivariate analysis:
(1) age of the patient in years
(2) CNS depression
(3) need for inotropic drug support to maintain the blood pressure (as a marker of significant persistent hypotension)
Parameter
|
Finding
|
Points
|
age of the patient in years
|
|
(age)
|
CNS depression
|
present after the 1st week
|
+1
|
|
absent after the 1st week
|
-1
|
inotropic drug support
|
required after the 1st week
|
+1
|
|
not required after the 1st week
|
-1
|
X =
= 3.2517 + (1.7243 * (points for CNS depression)) + (8.3925 * (points for inotropic drug support)) + (0.0876 * (age in years))
probability of survival =
= 1 / (1 + EXP(X))
where:
• The usual expression would be 1 / (1 + EXP((-1) * X)). Thus, advanced age and the presence of the other 2 risk factors exert a negative influence on survival.
• Other adverse risk factors affecting survival were sepsis, heart failure, jaundice (liver failure), malnutrition, and respiratory failure (requirement for mechanical ventilation).
Limitation:
• The score was formulated over 15 years ago, and survival is likely to have improved in the interval.