Maddrey discriminant function

Severity of alcohol-associated hepatitis — who may benefit from corticosteroids

Sources last checked: 2026-10-13

Maddrey discriminant function

Severity of alcohol-associated hepatitis — who may benefit from corticosteroids

Prothrombin time (patient) (s)Prothrombin time (laboratory control) (s)Total bilirubin (µmol/L)mg/dL × 17.1 = µmol/L

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Needs the prothrombin time in seconds and the local control value — not the INR or Quick %. Carithers used DF > 32; guidelines quote ≥ 32.

Source: Carithers RL Jr et al. Methylprednisolone therapy in patients with severe alcoholic hepatitis. A randomized multicenter trial. Ann Intern Med 1989;110(9):685-690 (modified DF with coefficient 4.6; original: Maddrey WC et al. Gastroenterology 1978;75:193-199).Open

Interpretation

< 32 — not severe	Below the DF threshold (≥ 32) at which corticosteroid therapy was studied (Carithers 1989).
≥ 32 — severe alcohol-associated hepatitis	High short-term mortality without treatment; in Carithers 1989 corticosteroids reduced mortality in this group (patients without contraindications). Response is assessed with the Lille model on day 7.

What is the Maddrey discriminant function?

The Maddrey discriminant function (DF) identifies severe alcohol-associated hepatitis from the prolongation of the prothrombin time and the bilirubin. Maddrey described it in 1978; the modified version with coefficient 4.6, used by Carithers et al. in 1989, defines severity as a DF of 32 or more.

When to use it

Suspected or confirmed alcohol-associated hepatitis with jaundice
Deciding whether corticosteroid treatment is worth considering
Trial eligibility (most trials use DF ≥ 32)

When not to use it

Other causes of jaundice or chronic liver disease
When only INR or Quick % is available and the PT in seconds cannot be obtained

How it is calculated

DF = 4.6 × (PT patient − PT control) [s] + bilirubin [µmol/L] ÷ 17.1 (= bilirubin in mg/dL).

Clinical pearls and limitations

Needs the prothrombin time in seconds and the local control value — not the INR or Quick %. Carithers used DF > 32; guidelines quote ≥ 32.
Needs PT in seconds and the laboratory control value — not the INR.
With bilirubin in µmol/L the formula divides by 17.1, as in Carithers' paper.
The Lille model on day 7 is the companion score for assessing response to corticosteroids.

Frequently asked questions

What Maddrey score is severe?

A discriminant function of 32 or more defines severe alcohol-associated hepatitis with high short-term mortality.

Can I use INR instead of prothrombin time?

Not directly — the formula uses the difference in seconds between patient and control prothrombin time.

What is the Maddrey formula?

4.6 × (patient PT − control PT in seconds) + bilirubin in mg/dL (or bilirubin µmol/L ÷ 17.1).

Evidence and guidelines

Primary source: Carithers RL Jr et al. Methylprednisolone therapy in patients with severe alcoholic hepatitis. A randomized multicenter trial. Ann Intern Med 1989;110(9):685-690 (modified DF with coefficient 4.6; original: Maddrey WC et al. Gastroenterology 1978;75:193-199).

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