MELD Score Calculator (Model for End-Stage Liver Disease)
Calculate MELD scores to assess the severity of chronic liver disease and determine liver transplant priority. The standard scoring system used worldwide for liver transplant allocation.
Laboratory Values
About MELD Score
The Model for End-Stage Liver Disease (MELD) is a scoring system used to assess the severity of chronic liver disease and prioritize patients for liver transplantation.
MELD was developed to:
- Predict short-term mortality in patients with chronic liver disease
- Allocate donor organs based on medical urgency rather than time on waiting list
- Standardize liver transplant prioritization globally
- Guide clinical decision-making in liver disease management
The score uses three laboratory values:
- Serum Creatinine: Reflects kidney function
- Total Bilirubin: Indicates liver's ability to process bilirubin
- INR: Measures blood clotting function
MELD scores range from 6 (least sick) to 40 (most sick), with higher scores indicating greater disease severity and higher transplant priority.
MELD Score Interpretation
| MELD Score | Disease Severity | 3-Month Mortality | Clinical Implications |
|---|---|---|---|
| 6-9 | Mild | 1.9% |
|
| 10-19 | Moderate | 6.0% |
|
| 20-29 | Severe | 19.6% |
|
| 30-39 | Very Severe | 52.6% |
|
| ≥40 | Critical | 71.3% |
|
The MELD score is calculated using the following formula:
MELD = 3.78 × ln(bilirubin) + 11.2 × ln(INR) + 9.57 × ln(creatinine) + 6.43
Key calculation notes:
- All laboratory values must be in mg/dL for bilirubin and creatinine
- If dialysis ≥2 times in the past week, creatinine is capped at 4.0 mg/dL
- Minimum values: creatinine 1.0, bilirubin 1.0, INR 1.0
- The result is rounded to the nearest integer
- Scores are capped between 6 and 40
The natural logarithm (ln) is used in the calculation, which means small changes in lab values can significantly impact the score at higher levels.
While MELD is widely used and validated, it has several limitations:
- Doesn't capture all complications:
- Hepatocellular carcinoma (uses exception points)
- Refractory ascites
- Hepatopulmonary syndrome
- Recurrent bacterial infections
- Laboratory limitations:
- Can be affected by anticoagulation therapy (INR)
- Acute kidney injury may falsely elevate score
- Dialysis timing affects creatinine interpretation
- Population-specific issues:
- May underestimate mortality in women
- Different accuracy across ethnic groups
- Age not directly incorporated
- Disease-specific limitations:
- Less accurate in acute liver failure
- May not reflect disease severity in some conditions (e.g., PBC, PSC)
For these reasons, many transplant centers use MELD exceptions and additional clinical criteria for listing decisions.
MELD-Na (MELD-Sodium) incorporates serum sodium levels into the traditional MELD score, as hyponatremia is associated with increased mortality in liver disease patients.
MELD-Na Benefits:
- Better predictor of mortality than MELD alone
- Accounts for sodium's role in liver disease prognosis
- Used by UNOS for liver allocation in the United States
- Particularly useful in patients with ascites
MELD-Na Calculation:
MELD-Na = MELD + 1.32 × (137 - Na) - [0.033 × MELD × (137 - Na)]
Where Na is serum sodium (capped between 125-137 mEq/L)
When MELD-Na is preferred:
- Liver transplant allocation (standard in US)
- Patients with hyponatremia
- Research and clinical trials
- When more precise mortality prediction is needed
Many centers are transitioning to MELD-Na as the primary scoring system due to its improved accuracy.
The frequency of MELD score updates depends on the clinical setting and patient status:
For transplant listing:
- MELD 25 or higher: Weekly lab updates
- MELD 19-24: Every 30 days
- MELD 11-18: Every 90 days
- MELD 10 or lower: Every 90 days
Clinical monitoring:
- Stable outpatients: Every 3-6 months
- Hospitalized patients: Every 1-7 days depending on acuity
- ICU patients: Daily to every other day
- After major interventions: Within 24-48 hours
Factors requiring more frequent monitoring:
- Recent decompensation events
- Active kidney dysfunction
- Starting new medications affecting liver/kidney function
- Post-procedure monitoring
- Consideration for bridge therapies
Important considerations:
- Scores can fluctuate due to temporary factors (dehydration, infections)
- Trends are often more important than single values
- Clinical status should always be considered alongside scores
Disclaimer
This calculator is provided for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.
- Always seek the advice of a qualified healthcare provider with any questions regarding a medical condition.
- Never disregard professional medical advice or delay seeking it because of information from this tool.
- Clinical decision-making should always incorporate the full clinical context, patient preferences, and local protocols.
- The creators of this tool accept no liability for decisions made based on its output.
If you are a patient: please discuss any results with your healthcare provider. This tool is designed for use by medical professionals and may not be appropriate for self-assessment.
References
- Kamath, P. S., & Kim, W. R. (2007). The model for end-stage liver disease (MELD). Hepatology, 45(3), 797-805.
- Wiesner, R., Edwards, E., Freeman, R., Harper, A., Kim, R., Kamath, P., ... & United Network for Organ Sharing Liver Disease Severity Score Committee. (2003). Model for end-stage liver disease (MELD) and allocation of donor livers. Gastroenterology, 124(1), 91-96.
- Kim, W. R., Biggins, S. W., Kremers, W. K., Wiesner, R. H., Kamath, P. S., Benson, J. T., ... & Therneau, T. M. (2008). Hyponatremia and mortality among patients on the liver-transplant waiting list. New England Journal of Medicine, 359(10), 1018-1026.
- Organ Procurement and Transplantation Network (OPTN). MELD Calculator and Allocation Policies.