CART Models of Speiser et al for a Patient with Acetaminophen-Induced Acute Liver Failure: Admission Model Based on Variables from King's College Criteria

 

Patient selection: acetaminophen-induced acute liver failure

 

Parameters on admission (designated Day 1):

(1) serum creatinine in mg/dL

(2) INR

(3) coma grade (from I to IV)

 

Arterial blood pH was a variable from the King's College criteria but was not used in the CART model.

Creatinine	INR	Coma	Mortality
< 1.5 mg/dL	NA	NA	26%
>= 1.5 mg/dL	< 1.75	NA	18%
>= 1.5 mg/dL	>= 1.75	Grade I or II	54%
>= 1.5 mg/dL	>= 1.75	Grade III or IV	74%

 

where:

• The cutoffs for each variable are different from those used for the King's College Criteria (KCC).

• The absence of coma is not included in the CART tree but added to the implementation.

 

Performance:

• The area under the ROC curve was 0.70 to 0.74.

• The same data in the King's College criteria had an area under the ROC curve of 0.56 to 0.59.

• The CART model is more sensitive and the KCC more specific.