MELD Score: Clinical Significance in Liver Disease Assessment
The MELD score is a validated, objective scoring system that predicts 3-month mortality in patients with end-stage liver disease and serves as the primary tool for prioritizing liver transplant allocation, with a threshold of MELD ≥15 recommended for transplant listing. 1
What the MELD Score Measures
The MELD score incorporates three objective laboratory parameters that reflect hepatic and renal function 1, 2:
- Serum bilirubin: Calculated as 3.8 × log(bilirubin in mg/dL), reflecting hepatic synthetic function 2
- International normalized ratio (INR): Calculated as 11.2 × log(INR), assessing coagulation function 2
- Serum creatinine: Calculated as 9.6 × log(creatinine mg/dL), representing renal function 2
The score operates on a continuous scale from 6 to 40, with higher scores correlating with increased mortality risk—ranging from approximately 90% survival at MELD 6 to only 7% survival at MELD 40 1, 3
Primary Clinical Applications
Liver Transplant Allocation
MELD ≥15 is the critical threshold for transplant listing, as patients with MELD ≤14 have better 1-year survival without transplantation than with it. 1
- The MELD score drives organ allocation in the United States and most European countries, prioritizing patients based on objective mortality risk rather than waiting time 1
- Implementation of MELD-based allocation in 2002 led to a sharp reduction in waiting list numbers and decreased mortality without affecting post-transplant survival 4
Mortality Prediction Across Clinical Scenarios
MELD accurately predicts short-term mortality in multiple contexts 1, 5:
- Decompensated cirrhosis 1
- Variceal bleeding 1, 5
- Hepatorenal syndrome 1, 5
- Hepatopulmonary syndrome 1
- Alcoholic hepatitis 5
- Acute liver failure 5
- Perioperative risk assessment for non-hepatic surgery or TIPS procedures 5
Critical Advantages Over Child-Turcotte-Pugh Score
MELD offers superior prognostic accuracy because it uses entirely objective laboratory-based criteria, provides a continuous numerical scale, and includes renal function—unlike the Child-Pugh score which relies on subjective clinical assessments. 1, 2
The Child-Pugh score includes subjective parameters (ascites severity, encephalopathy grade) that introduce variability, whereas MELD eliminates observer bias 2. The concordance statistic for MELD (0.83) significantly exceeds that of Child-Pugh (0.76) in predicting 3-month mortality 6.
Management Algorithm Based on MELD Score
MELD ≥15: High-Risk Population Requiring Immediate Action
Patients with MELD ≥15 require immediate referral for liver transplantation evaluation. 1
- Engage a multidisciplinary transplant team for comprehensive assessment 1
- Identify and aggressively treat acute complications (variceal bleeding, spontaneous bacterial peritonitis, hepatorenal syndrome) 7
- Monitor MELD score regularly (every 1-3 months depending on stability) to track disease progression 1
- Consider MELD exception points if hepatocellular carcinoma or other qualifying conditions are present 1
MELD <15: Lower-Risk Population
Focus on complication management rather than urgent transplant evaluation 1:
- Regular monitoring for disease progression with serial MELD calculations 1
- Treat specific cirrhosis complications (ascites, encephalopathy, varices) with standard medical management 1
- Consider transplant evaluation if major complications occur despite optimal medical management, even with low MELD scores 1
Important Limitations and Clinical Pitfalls
Conditions Requiring MELD Exception Points
Certain conditions warrant "exception points" because MELD inadequately reflects their mortality risk or transplant benefit. 1
- Hepatocellular carcinoma
- Hepatopulmonary syndrome
- Portopulmonary hypertension
- Refractory ascites
Laboratory-Based Pitfalls
Serum creatinine can be unreliable in cirrhotic patients, potentially overestimating renal dysfunction in patients with sarcopenia or underestimating it in those with fluid overload. 1
- Patients on renal replacement therapy receive a maximum creatinine value of 4.0 mg/dL in the calculation 1
- Recent evidence shows that patients with creatinine-driven MELD scores (MELD-Cr subtype) have significantly lower 1-year intent-to-treat survival (65%) compared to bilirubin-driven (78%) or INR-driven (75%) subtypes, even at equivalent MELD scores 8
Very High MELD Scores
MELD scores >30-35 are associated with increased post-transplant mortality and morbidity, requiring careful assessment of transplant candidacy. 1
Absolute contraindications at very high MELD include 1:
- Lactate >9 mmol/L
- Severe respiratory failure
- Increasing vasopressor support
Enhanced MELD Variations
MELD-Na (Current Standard in U.S.)
MELD-Na improves mortality prediction by incorporating serum sodium, as hyponatremia is an independent predictor of death in patients with cirrhosis and ascites. 1
- MELD-Na is particularly superior in patients with low MELD scores where hyponatremia may not be adequately captured 1
- The United States currently uses MELD-Na as the prioritization system for deceased donor liver allocation 1
MELD 3.0 (Latest Evolution)
MELD 3.0 incorporates serum albumin and patient sex to reduce gender disparities and improve prediction, with women receiving approximately 1.3 additional points. 3
- MELD 3.0 demonstrates superior discrimination compared to MELD-Na, with a concordance statistic of 0.869 versus 0.862 (p<0.01) 3
- The American Association for the Study of Liver Diseases and European Association for the Study of the Liver recommend MELD 3.0 for improved mortality prediction 3
Common Clinical Pitfalls to Avoid
Do not use MELD as the sole criterion for transplant listing in patients with hepatocellular carcinoma or other MELD exceptions. 1
Do not ignore clinical decompensation in patients with low MELD scores—complications such as spontaneous bacterial peritonitis (median survival <1 year) or type I hepatorenal syndrome (median survival <2 weeks) carry grave prognosis regardless of MELD score 7, 1