🧪 Maddrey's Discriminant Function Calculator
Calculate Maddrey's Discriminant Function (MDF) to evaluate the severity and prognosis of alcoholic hepatitis. Determine whether corticosteroid treatment is indicated.
📊 Maddrey's Discriminant Function Results
What Is Alcoholic Hepatitis?
Alcoholic hepatitis is a severe form of acute liver injury caused by heavy alcohol consumption. This disease is associated with significant morbidity and mortality and typically affects young and middle-aged adults.
Symptoms depend on the extent of liver damage and may include:
- Fatigue and general weakness
- Weight loss and changes in appetite
- Pain or swelling in the abdomen
- Yellowing of the skin or eyes (jaundice)
A patient who develops this condition should stop drinking alcohol. Various drug therapies are also available, including corticosteroids, pentoxifylline, or N-acetylcysteine.
Different prognostic tools have been developed to predict disease severity, like the MELD score (Model for End-Stage Liver Disease) or Maddrey's Discriminant Function.
Maddrey's Discriminant Function
Maddrey's Discriminant Function is a formula created by Maddrey and colleagues in 1978. It evaluates the severity and prognosis in alcoholic hepatitis and assesses which patients will benefit from steroid treatment.
The calculator uses only three variables:
- Patient's prothrombin time (PT) — in seconds
- Reference prothrombin time — usually 11–13 seconds
- Serum bilirubin level — in mg/dL
A Maddrey's discriminant function score ≥ 32 is interpreted as a poor outcome and indicates the patient may benefit from corticosteroid therapy.
Prothrombin Time
Prothrombin time (PT) is a blood test that measures how long it takes for blood to clot. Together with the international normalized ratio (INR), it is used to measure warfarin dosage, assess liver damage, and vitamin K status.
The reference value for prothrombin time depends on the analytical method used and usually ranges from 11 to 13 seconds.
Bilirubin Level
Bilirubin is a yellow compound in the blood that forms after red blood cells break down. Bilirubin travels through the liver, gallbladder, and digestive tract and is excreted in bile and urine.
Reference values for total serum bilirubin range from 0.1 to 1.2 mg/dL. Increased bilirubin levels may be associated with liver disease and other conditions, e.g., Gilbert's syndrome.
Unit conversion: 1 mg/dL = 17.1 µmol/L
Practical Example
Let's calculate the discriminant function for a patient with a bilirubin level of 2 mg/dL and a prothrombin time of 14 seconds, with a reference PT of 12 seconds:
Step 1: Apply the formula
Step 2: Substitute values
Step 3: Calculate
Result: MDF = 11.2 — this score is below 32, indicating a good prognosis. ✅
Interpretation
| MDF Score | Interpretation | Action |
|---|---|---|
| < 32 | Good prognosis | Supportive care, abstinence from alcohol, nutritional support |
| ≥ 32 | Poor prognosis (high mortality risk) | Consider corticosteroid therapy (prednisolone 40mg/day for 28 days) |
Frequently Asked Questions
What is a normal MDF score?
An MDF score below 32 generally indicates a good prognosis. The lower the score, the better the expected outcome. A score of 0 or near 0 suggests minimal liver dysfunction.
When should corticosteroids be given?
Corticosteroid therapy (typically prednisolone) is recommended for patients with an MDF ≥ 32, as these patients have a significantly higher mortality risk and have been shown to benefit from steroid treatment.
What is the reference PT for MDF?
The reference PT is the control prothrombin time used by the laboratory performing the test. It typically ranges from 11 to 13 seconds, but always use the specific value provided by your lab.