Child-Pugh score calculator

What the Child-Pugh score is for

Cirrhosis is a long-term condition, and two people with the same diagnosis can have very different liver function. The Child-Pugh score gives clinicians, nurses and students a shared shorthand for how much function is left. It also has a second job outside the ward: regulators use it to group people with liver impairment when testing how drugs behave in the body, which the FDA document describes. A score is only as good as its inputs, so read the next sections before relying on the number.

What is the Child-Pugh score?

The Child-Pugh score, also called the Child-Turcotte-Pugh (CTP) score, grades how well the liver is working in a person with cirrhosis. It adds up points for five findings: total bilirubin, serum albumin, clotting (INR or prothrombin time), ascites and hepatic encephalopathy. Each is scored from 1 to 3, so the total runs from 5 to 15. The total is then grouped into class A, B or C.

How are the classes defined?

Class A is 5 to 6 points, class B is 7 to 9 and class C is 10 to 15. The US Food and Drug Administration, in its draft guidance on studying drugs in liver impairment, calls these mild, moderate and severe impairment. The guidance notes that the classification “continues to be a useful marker of liver function” while pointing to limitations such as the subjective assessment of ascites.

What are the cut-offs for each item?

For 1, 2 and 3 points: bilirubin below 2, 2 to 3, above 3 mg/dL; albumin above 3.5, 2.8 to 3.5, below 2.8 g/dL; INR below 1.7, 1.7 to 2.3, above 2.3 (or the prothrombin time prolonged by less than 4, 4 to 6, more than 6 seconds over control); ascites absent, slight, moderate; encephalopathy none, grade 1 or 2, grade 3 or 4. A value that sits exactly on a boundary, such as a bilirubin of exactly 2.0 or 3.0, scores in the middle group, as the published ranges “2 to 3” include both ends.

Where does the score come from?

Child and Turcotte proposed a classification to judge the operative risk of portosystemic shunt surgery. It used ascites, encephalopathy, nutritional status, bilirubin and albumin. Pugh and colleagues, in the British Journal of Surgery in 1973, replaced nutritional status with a clotting measure (prothrombin time) and gave each item a score, creating the version used today. Their paper was about people having the oesophagus transected for bleeding varices, not about general prognosis.

INR or prothrombin time: which should I use?

Pugh’s original table used the number of seconds the prothrombin time was prolonged over a control. Later versions, including the FDA table, accept an INR instead and list both. The page lets you choose. The two are not interchangeable in a single patient on an arbitrary day, but each is read against its own column. In the worked example below a prolongation of 5 seconds gives 2 points, the same as an INR of 1.7 to 2.3.

What does a class mean for survival?

Survival percentages for each class are often quoted online, but we could not trace them to a source we were able to open, so this page does not show them. What the sources we read do say is narrower: a 2016 systematic review (Peng and colleagues) describes the Child-Pugh score as widely used to assess severity of liver dysfunction, and the FDA guidance uses it to group patients for drug studies. Ask a clinician what the class means for a particular person.

How does Child-Pugh differ from MELD?

Child-Pugh uses two judgments (ascites and encephalopathy) that can vary between examiners and with treatment such as diuretics or lactulose. MELD uses only laboratory values on a continuous scale. The 2016 meta-analysis cited below found that studies disagreed about which predicts outcomes better. The two scores answer slightly different questions, and many clinical settings report both.

Worked example

A person with bilirubin 1.5 mg/dL, albumin 3.8 g/dL, INR 1.2, no ascites and no encephalopathy gets 1 point for each item: 5 points, class A. A second person has bilirubin 2.5 (2 points), albumin 3.2 (2), INR 1.5 (1), slight ascites (2) and no encephalopathy (1): 8 points, class B. A third has bilirubin 4.0, albumin 2.5, INR 2.5, moderate ascites and grade 1 or 2 encephalopathy. That is 3 + 3 + 3 + 3 + 2 = 14 points, class C.

Limits of this method

Two of the five items are not measured but judged. The FDA draft guidance points out that ascites assessment is subjective, and a 2016 meta-analysis adds that both ascites and encephalopathy depend on the examiner and on treatment, and that INR varies from laboratory to laboratory and does not fully reflect clotting problems in cirrhosis. The score treats a bilirubin of 2.1 and 2.9 the same, and 3.1 jumps to the top group, which is why it is a coarse grading rather than a smooth measure. It was devised in a surgical population in 1973.

Common mistakes

The FDA guidance lists situations where the lab values can mislead: vitamin K deficiency or anticoagulant drugs raise the INR, Gilbert’s syndrome raises bilirubin through unconjugated bilirubin, and intravenous fluids can dilute the serum albumin. In each case a point is earned for something other than liver function. Other slips are entering bilirubin in µmol/L (divide by 17.1 first) or albumin in g/L (divide by 10), and scoring encephalopathy by how tired someone looks rather than by the clinical grade.

Sources: Pugh RNH, Murray-Lyon IM, Dawson JL, Pietroni MC, Williams R, “Transection of the oesophagus for bleeding oesophageal varices,” Br J Surg 1973;60:646–649 (original paper not opened; the table is as printed in the FDA document); U.S. Food and Drug Administration, draft guidance for industry Pharmacokinetics in Patients with Impaired Hepatic Function: Study Design, Data Analysis, and Impact on Dosage, Table 1; Peng Y, Qi X, Guo X, “Child-Pugh versus MELD score for the assessment of prognosis in liver cirrhosis: a systematic review and meta-analysis,” Medicine (Baltimore) 2016;95:e2877. Related: MELD score, FIB-4 index, Glasgow Coma Scale.

For general information only — not medical advice, and not a tool for patient care decisions. Talk with a doctor about any liver score. How we check our calculators.