MELDscores

MELD scores, formally the Model for End-Stage Liver Disease scores, are a numerical tool used to estimate short-term mortality in patients with advanced liver disease and to prioritize them for liver transplantation. The score is derived from routinely obtained laboratory values and aims to standardize waitlist prioritization across diverse diseases and institutions.

Origin and formula: The MELD score was developed from data on adult liver transplant candidates and introduced by Kamath and colleagues in 2001. The original calculation uses the natural logarithms of serum bilirubin (mg/dL), international normalized ratio (INR), and serum creatinine (mg/dL), plus a constant: MELD = 3.78 × ln(bilirubin) + 11.2 × ln(INR) + 9.57 × ln(creatinine) + 6.43, with values below 1 adjusted to 1 to avoid negative logs. The score typically ranges from about 6 to 40, with higher values indicating greater 3-month mortality risk. A MELD-Na variant adds serum sodium to improve prediction, and a Pediatric End-Stage Liver Disease (PELD) score is used for children.

Applications and policy: In many transplant systems, MELD or MELD-Na scores drive allocation decisions, prioritizing patients at highest short-term mortality risk for liver transplantation. Exceptions may be granted for certain conditions (for example, hepatocellular carcinoma or acute liver failure) to account for risks not fully captured by the score.

Limitations: While useful for predicting short-term mortality, MELD has limitations. It does not capture frailty, functional status, infections, or some nonhepatic factors, and lab variability or specific disease etiologies can affect accuracy. Ongoing refinements include the incorporation of sodium (MELD-Na) and pediatric adaptations (PELD).