Discriminant Function = 4.6 * (Prothrombin Time (seconds) - Control Time (seconds)) + Serum Bilirubin (mg/dL) (1)

A discriminant function > 32 indicates severe alcoholic hepatitis.

A clinician's judgement can not be replaced by a computer's analysis.

Ask your local lab about control time and prothrombin time. Usually, it's 13-14.
Lille Model - analyzes effectiveness to corticosteroid therapy after seven days.
Meld Model - >21 indicates severe alcoholic hepatitis.
Prothrombin Time

Sources:
1. GI/Liver Secrets: with STUDENT CONSULT Access
2. Lucey MR, Mathuren P, Morgan TR. Alcoholic Hepatitis. NEJM. 2009; 360: 2758-2769.