What is the MELD Score?
The Model for End-Stage Liver Disease (MELD) score is a numerical scale used to assess the severity of chronic liver disease. Originally developed at the Mayo Clinic to predict survival in patients undergoing transjugular intrahepatic portosystemic shunt (TIPS) procedures, it was adopted by the United Network for Organ Sharing (UNOS) in 2002 as the primary tool for prioritizing liver transplant allocation in the United States.
The MELD score uses three laboratory values — serum creatinine, total bilirubin, and INR — to generate a score from 6 to 40. Higher scores indicate more severe liver disease and higher urgency for transplantation. The score predicts 3-month mortality risk without transplant.
The MELD score replaced the older Child-Turcotte-Pugh (CTP) classification, which relied partly on subjective assessments (ascites severity and encephalopathy grade). MELD's advantage is that it uses only objective, reproducible laboratory values.
MELD Formula
Important calculation rules:
- All values below 1.0 are set to 1.0 for the calculation (since ln of values less than 1 is negative)
- Serum creatinine is capped at 4.0 mg/dL
- If the patient has been on dialysis at least twice in the past week or has received CVVHD for 24+ hours, creatinine is automatically set to 4.0 mg/dL
- The final result is rounded to the nearest integer
- Maximum score is 40
Score Interpretation
| MELD Score | 3-Month Mortality | Severity | Clinical Implication |
|---|---|---|---|
| 6 – 9 | 1.9% | Low | Routine monitoring; transplant not immediately indicated |
| 10 – 19 | 6.0% | Moderate | Regular follow-up; consider transplant evaluation |
| 20 – 29 | 19.6% | High | Active transplant listing recommended |
| 30 – 39 | 52.6% | Very High | High-priority transplant candidate |
| ≥ 40 | 71.3% | Critical | Highest urgency; UNOS Status 1 consideration |
MELD Severity Diagram
MELD-Na (Sodium-Adjusted)
In 2016, UNOS adopted the MELD-Na score, which incorporates serum sodium into the calculation. Hyponatremia (low sodium) is an independent predictor of mortality in liver disease patients and is common in advanced cirrhosis due to impaired free water excretion.
Sodium values are bounded: if Na < 125, use 125; if Na > 137, use 137. The MELD-Na score better predicts 90-day waitlist mortality compared to the original MELD formula, particularly for patients with moderate MELD scores (15–25) who have low sodium levels.
End-Stage Liver Disease
End-stage liver disease (ESLD) represents the final phase of progressive liver damage where the liver can no longer perform its essential functions. Common causes include:
- Chronic hepatitis C: Historically the leading cause of ESLD and liver transplantation. New direct-acting antiviral therapies have dramatically improved treatment outcomes.
- Alcohol-associated liver disease: Now the leading indication for liver transplantation in the United States, surpassing hepatitis C.
- Non-alcoholic steatohepatitis (NASH): Rapidly increasing as a cause of ESLD, associated with obesity, diabetes, and metabolic syndrome.
- Chronic hepatitis B: A major cause of ESLD worldwide, particularly in Asia and Africa.
- Autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis
- Hereditary conditions: Hemochromatosis, Wilson disease, alpha-1 antitrypsin deficiency
Complications of ESLD include portal hypertension, ascites, variceal bleeding, hepatic encephalopathy, hepatorenal syndrome, and hepatocellular carcinoma. Management focuses on treating complications, screening for cancer, and evaluating candidacy for liver transplantation.
Liver Transplant Allocation
In the United States, donor livers are allocated based on the MELD-Na score through a system managed by UNOS and the Organ Procurement and Transplantation Network (OPTN). Key principles include:
- Sickest first: Patients with the highest MELD scores receive offers first, reflecting the urgency of their medical need.
- Blood type compatibility: ABO-identical or compatible donors are matched to recipients.
- Geographic proximity: The 2019 Acuity Circles policy distributes organs within 150, 250, and 500 nautical mile circles before broader sharing.
- Exception points: Patients with hepatocellular carcinoma (HCC) or other conditions not well-captured by laboratory MELD receive standardized exception points.
- Minimum listing score: Generally, patients need a MELD of at least 15 to be listed, as the risk of transplant surgery outweighs the benefit at lower scores.
Frequently Asked Questions
What MELD score is needed for a liver transplant?
There is no absolute cutoff, but patients are generally listed when their MELD score reaches 15 or higher, as this is the point where the survival benefit of transplantation exceeds the surgical risk. In practice, median MELD at transplant varies by region and blood type but is typically in the mid-20s to low 30s.
How often is the MELD score recalculated?
UNOS requires recertification at intervals based on the current score: every 12 months for MELD <10, every 3 months for MELD 11–18, every month for MELD 19–24, and every 7 days for MELD ≥25. This ensures the most urgent patients have up-to-date scores.
Can MELD score improve?
Yes. If the underlying cause of liver disease is treated (e.g., alcohol abstinence, antiviral therapy for hepatitis, treating infections), liver function can improve and the MELD score can decrease. This is one reason for frequent score recalculation.
What is the difference between MELD and Child-Pugh?
The Child-Turcotte-Pugh (CTP) score uses five parameters (bilirubin, albumin, INR, ascites, encephalopathy), two of which are subjectively assessed. The MELD score uses only three objective laboratory values, making it more reproducible. MELD is used for transplant allocation, while CTP is still used in some clinical and research contexts to classify cirrhosis severity (Class A, B, or C).