Maddrey’s Discriminant Function Calculator
Prognostic Tool for Alcoholic Hepatitis
What is Maddrey’s Discriminant Function?
Maddrey’s Discriminant Function (MDF), also known simply as the Discriminant Function, is a prognostic scoring system used to assess the severity and predict outcomes in patients with alcoholic hepatitis. Developed by Dr. Willis Maddrey and colleagues in 1978, it remains one of the most widely used tools for evaluating this condition.
The MDF score helps identify patients with severe alcoholic hepatitis who have a high short-term mortality risk and may benefit from specific treatments like corticosteroids.
Clinical Significance
Alcoholic hepatitis is an acute inflammatory liver injury associated with high mortality. The MDF score helps clinicians stratify patients by risk, identifying those with severe disease (MDF ≥32) who have significantly higher 30-day mortality and may benefit from corticosteroid therapy.
Calculation Parameters
The MDF score is calculated using two laboratory values:
| Parameter | Significance |
|---|---|
| Prothrombin Time (PT) | Reflects the liver’s synthetic function; prolonged PT indicates impaired coagulation factor production |
| Total Bilirubin | Measures the liver’s ability to process bile; elevated levels indicate severe liver injury and impaired excretion |
Maddrey’s Discriminant Function Formula
Where PT is measured in seconds. If using INR instead of PT, the formula can be adapted as follows:
Historical Context
The MDF score was developed based on a study of 55 patients with alcoholic hepatitis. Researchers found that the combination of bilirubin level and prothrombin time provided the best discrimination between survivors and non-survivors. The cutoff of 32 was established based on its ability to identify patients with a poor prognosis who might benefit from specific interventions.
MDF Calculator
Enter the patient’s laboratory values to calculate the Maddrey’s Discriminant Function score and assess prognosis in alcoholic hepatitis.
Score Interpretation
MDF scores are categorized into risk levels with associated clinical implications:
Treatment Implications
For MDF ≥ 32: Consider prednisolone 40 mg daily for 28 days, followed by a taper or discontinuation, provided there are no contraindications such as active infection, gastrointestinal bleeding, or renal failure.
Several clinical trials, including the landmark STOPAH trial, have demonstrated that patients with MDF ≥32 who receive corticosteroids have improved short-term survival compared to those who do not.
Limitations and Considerations
While the MDF score is a valuable prognostic tool, it should be used in conjunction with:
- Clinical assessment for signs of hepatic decompensation
- Evaluation for contraindications to corticosteroid therapy
- Assessment of other prognostic scores like MELD or GAHS
- Consideration of patient preferences and overall clinical context
Comparison with Other Scores
While MDF is specific to alcoholic hepatitis, other scoring systems may provide additional prognostic information:
- MELD Score: More comprehensive but not specific to alcoholic hepatitis
- Glasgow Alcoholic Hepatitis Score (GAHS): Incorporates additional variables like age and white blood cell count
- Lille Model: Used after 7 days of corticosteroid therapy to assess response
Note: This calculator provides an estimate based on the standard MDF calculation. Treatment decisions should always be made in consultation with a hepatology specialist considering the complete clinical picture.
