Hepatology

A non-invasive index using AST (relative to its upper limit of normal) and platelet count to estimate liver fibrosis. WHO hepatitis B guidance uses APRI greater than 2 to identify cirrhosis in adults in resource-limited settings; lower cutoffs (around 0.5 and 1.5) are used to rule out or rule in significant fibrosis, with the usual sensitivity and specificity trade-offs.

The Child-Pugh score grades cirrhosis severity from five variables (bilirubin, albumin, INR, ascites, and encephalopathy), each scored 1 to 3. The total of 5 to 15 maps to Class A, B, or C, which correlates with survival and surgical risk and is still widely used in hepatology.

A non-invasive index combining age, AST, ALT, and platelet count to estimate the likelihood of advanced hepatic fibrosis, widely used as the first step in triaging chronic liver disease before elastography or biopsy.

The Maddrey discriminant function (mDF) grades the severity of alcohol-associated hepatitis from the prothrombin time prolongation and total bilirubin. A value of 32 or above identifies severe disease with high short-term mortality and is the classic threshold for considering corticosteroid therapy.

MELD-Na adds serum sodium to the classic MELD model (bilirubin, INR, creatinine), capturing the prognostic weight of hyponatraemia in cirrhosis. It estimates 90-day mortality and was used by OPTN for liver allocation from 2016 until MELD 3.0 superseded it.