MELD Calculator

Model of End Stage Liver Disease

The MELD score assesses the severity of the chronic liver disease and is used in the liver transplant waiting list prioritization by the United Network for Organ Sharing (UNOS).

The variables used by the MELD calculator are:

• International normalized ratio time (INR);
• Serum creatinine;
• Serum bilirubin;
• Haemodialysis twice in the past week;
• Serum sodium (2016 formula inclusion).

The formula resulted from the original study referenced below is:

Original MELD Score = 10 x [(0.957 x ln(Creatinine)) + (0.378 x ln(Bilirubin)) + (1.12 x ln(INR))] + 6.43

In January 2016, OPTN changed Policy 9.1 in regard to the calculation of the MELD score to include serum sodium (measured in mEq/L and in case the patient is known hyperglicemic, sodium correction may be needed for glucose levels above 120 mg/dL).

Therefore, the new formula is:

MELD Score (2016) = MELD(i) + 1.32 x (137-Na) – [0.033 x MELD(i) x (137-Na)]

Regardless of the formula used, there are three adjustments to be made:

• Values less than 1 are automatically adjusted to the lower limit value of 1 to prevent obtaining a negative score.
• The upper limit for serum creatinine is 4 mg/dL, therefore for those patients that have had 2 rounds of dialysis in the past week, the value is automatically adjusted to 4 mg/dL.
• Sodium values less than 125 mmol/L will be set to 125, and values greater than 137 mmol/L will be set to 137.

MELD interpretation

The result obtained after the formulas are applied is presented with its corresponding 3-month mortality percentage (based on original MELD).

MELD scores are also calculated as part of the prioritization process of UNOS for liver transplant waiting lists.

About the original study

MELD was created as a mean to quantitatively assess the severity of liver disease and to be used in determining priorities in allocation liver transplantion.

The original study aimed to produce a similar model to that created for the survival stratification of patients undergoing the transjugular intrahepatic portosystemic shunt (TIPS).

MELD validity was tested in 4 independent data sets:

• Patients hospitalized for hepatic decompensation;
• Ambulatory patients with noncholestatic cirrhosis;
• Patients with primary biliary cirrhosis (PBC);
• Unselected patients with cirrhosis from the historic 1980s set.

The MELD performed well in predicting death within 3 months in all four validation sets. One finding was that the model is not influenced by individual complications, such as portal hypertension.

Original source

Kamath PS, Wiesner RH, Malinchoc M, Kremers W, Therneau TM, Kosberg CL, D'Amico G, Dickson ER, Kim WR. A model to predict survival in patients with end-stage liver disease. Hepatology. 2001; 33(2):464-70.

Validation

Wiesner R, Edwards E, Freeman R, Harper A, Kim R, Kamath P, Kremers W, Lake J, Howard T, Merion RM, Wolfe RA, Krom R; United Network for Organ Sharing Liver Disease Severity Score Committee. Model for end-stage liver disease (MELD) and allocation of donor livers. Gastroenterology. 2003; 124(1):91-6.

Other references

1. Kamath PS, Kim WR; Advanced Liver Disease Study Group. The model for end-stage liver disease (MELD). Hepatology. 2007; 45(3):797-805.

2. Kremers WK, van IJperen M, Kim WR, Freeman RB, Harper AM, Kamath PS, Wiesner RH. MELD score as a predictor of pretransplant and posttransplant survival in OPTN/UNOS status 1 patients. Hepatology. 2004; 39(3):764-9.