Model for End-Stage Liver Disease (MELD) Score
The MELD score is a numerical scale ranging from 6 (less ill) to 40 (gravely ill) that uses three objective laboratory values—serum bilirubin, serum creatinine, and international normalized ratio (INR)—to predict short-term mortality risk in patients with end-stage liver disease. 1
Calculation and Components
The MELD score is calculated using the following formula:
MELD = 3.78 × log(bilirubin in mg/dL) + 11.2 × log(INR) + 9.6 × log(creatinine mg/dL) + 6.4 2
Important calculation rules:
- If any laboratory value is less than 1.0, use 1.0 instead
- Serum creatinine is capped at 4.0 mg/dL
- Special considerations apply for patients who have had dialysis twice within the last week 2
Primary Clinical Applications
Liver Transplantation
- The MELD score was adopted by the United Network for Organ Sharing (UNOS) to prioritize patients on the liver transplantation waiting list according to their risk of death within 3 months 1
- Implementation of MELD-based allocation in 2002 led to reduced mortality on transplant waiting lists 3
- A MELD score ≥15 is generally recommended for listing patients with end-stage liver disease for transplantation 1
Prognostic Assessment
- Predicts 90-day mortality in patients with cirrhosis 3
- Helps determine when to refer patients for transplantation evaluation
- Patients should be referred when they develop evidence of hepatic dysfunction (MELD >10) or experience their first major complication (ascites, variceal bleeding, or hepatic encephalopathy) 1
Interpretation of MELD Scores
- 6-9: 1.9% 3-month mortality risk
- 10-19: 6% 3-month mortality risk
- 20-29: 19.6% 3-month mortality risk
- 30-39: 52.6% 3-month mortality risk
- 40+: 71.3% 3-month mortality risk
In patients with MELD <14,1-year survival was lower with transplantation than without, suggesting transplantation may not be beneficial for these patients 1
Advantages Over Other Scoring Systems
The MELD score offers several advantages over the Child-Pugh score:
- Based entirely on objective laboratory tests 1
- Includes measurement of renal function (serum creatinine), which is an important prognostic marker 1
- Not affected by subjective clinical assessments 1
Limitations and Pitfalls
Renal dysfunction impact: The MELD-Cr subtype (where creatinine is the dominant driver of the score) is associated with higher waitlist mortality and lower transplant rates compared to other MELD subtypes 4
Gender disparities: Women with the same MELD score as men have lower intent-to-treat survival rates, particularly in the MELD-Cr subtype 4
Disease-specific variations: The MELD score may predict mortality differently based on the underlying liver disease:
- Better prediction for non-cholestatic liver diseases
- Less accurate for cholestatic diseases 5
Missing clinical factors: Does not account for complications like hepatic encephalopathy, ascites, or portal hypertension 1
Artificial elevation: May be artificially elevated in patients with renal failure or those taking anticoagulants, which doesn't necessarily reflect liver disease severity 2
Recent Developments: MELD 3.0
A newer version called MELD 3.0 has been developed that includes:
- Patient sex
- Serum albumin levels
- New weights for serum sodium, bilirubin, INR, and creatinine
This updated score is expected to reduce overall waitlist mortality and improve access for female liver transplant candidates 6
Exceptions to MELD
Several conditions may qualify for MELD exceptions (extra points) in transplant allocation:
- Hepatocellular carcinoma
- Hepatopulmonary syndrome
- Portopulmonary hypertension
- Recurrent cholangitis
- Familial amyloidotic polyneuropathy
- Primary oxaluria 1
The MELD score has become the standard tool for assessing liver disease severity and prioritizing liver transplantation, with ongoing refinements to improve its accuracy and equity across different patient populations.