Model for End-Stage Liver Disease

The Model for End-Stage Liver Disease, or MELD, is a scoring system for assessing the severity of

MELD uses the patient's values for serum bilirubin, serum creatinine, and the international normalized ratio for prothrombin time (INR) to predict survival. It is calculated according to the following formula:^[3]

${\displaystyle \mathrm {MELD} {\overset {\mathrm {def} }{=}}3.78\times \ln \left({\text{serum bilirubin (mg/dL)}}\right)+11.2\times \ln({\text{INR}})+9.57\times \ln \left({\text{serum creatinine (mg/dL)}}\right)+6.43}$

MELD scores are reported as whole numbers, so the result of the equation above is rounded.

UNOS has made the following modifications to the score:^[5]

• If the patient has been dialyzed twice within the last 7 days, then the value of serum creatinine should be 4.0 mg/dL
• Any value less than one is given a value of 1 (i.e. if bilirubin is 0.8 a value of 1.0 is used) to prevent subtraction from any of the three factors, since the natural logarithm of a positive number below 1 (greater than 0 and less than 1) yields a negative value.

The etiology of liver disease was subsequently removed from the model because it posed difficulties such as how to categorize patients with multiple causes of liver disease. Modification of the MELD score by excluding etiology of liver disease did not significantly affect the model's accuracy in predicting three-month survival.

Patients with a diagnosis of liver cancer will be assigned a MELD score based on how advanced the cancer is. ^{[citation needed]}

Interpretation

In interpreting the MELD Score in hospitalized patients, the 3 month observed mortality (considering 3,437 adult liver transplant candidates with chronic liver disease who were added to the OPTN waiting list at 2A or 2B status between November, 1999, and December, 2001) is:^[6]

Applications of MELD score include:

• The best outcomes with TIPS occur among patients with a MELD score less than 14.
• Patients with MELD scores greater than 24 who are reasonable liver transplant candidates are probably best served by foregoing TIPS placement.

History

MELD was originally developed at the Mayo Clinic by Dr. Patrick Kamath, and at that point was called the "Mayo End-stage Liver Disease" score. It was derived in a series of patients undergoing TIPS procedures. The original version also included a variable based on the underlying etiology (cause) of the liver disease.^[1] The score turned out to be predictive of prognosis in chronic liver disease in general, and—with some modifications—came to be applied as an objective tool in assigning need for a liver transplant. The etiology turned out to be relatively unimportant, and was also regarded as relatively subjective; it was therefore removed from the score.^[3]

The successor of MELD, an advanced scoring system, made by collaboration between Massachusetts General Hospital and IBM, called MELD-Plus was introduced in 2017.^[7]

Potential of alternative scores to extend life expectancy

The

• Pediatric End-Stage Liver Disease
• Milan criteria
• Child-Pugh score
• MELD-Plus
• MELD-Na
• MELD 3.0

References