Child-Pugh score

The Child-Pugh score is a scale that estimates how impaired liver function is in a person with cirrhosis. It combines five simple pieces of information, three from blood tests and two from the patient’s examination, and uses them to sort the disease into three groups of increasing severity: class A, class B and class C.

If you or a family member were told about a “Child class” or a “Child score,” this is what it refers to. In plain terms, class A corresponds to compensated cirrhosis, with the liver still working well; classes B and C reflect greater deterioration. It is a guiding tool that helps the physician estimate prognosis and make decisions, not a verdict on any single person.

Dr. Charles Gardner Child III (1908-1991)

Where does this classification come from?

The original scale was proposed by Child and Turcotte in 1964 to estimate the risk of patients with cirrhosis who were going to have surgery for portal hypertension. In 1973, Pugh and colleagues modified it: they replaced nutritional status with prothrombin time, which can be measured objectively. That version, known as Child-Pugh or modified Child, is the one still used today.

Two points are worth keeping in mind. The scale was created to assess surgical risk, and it applies only to patients with cirrhosis, not to other liver diseases.

The five variables

The score adds up five parameters. Each one receives 1, 2 or 3 points depending on its severity, so the total ranges from 5 (best) to 15 (worst).

• Bilirubin: reflects the liver’s ability to process and clear bile pigments. When it rises, jaundice appears (yellow color of the skin and eyes).
• Albumin: a protein made by the liver. A low value means the liver is producing less than needed.
• INR or prothrombin time: measures blood clotting, which depends on proteins made by the liver. An abnormal value signals that this function is impaired.
• Ascites: buildup of fluid in the abdomen. It is scored according to whether it is absent, mild or hard to control.
• Encephalopathy: disturbed brain function caused by toxins the liver can no longer clear well. It ranges from mild confusion to deep drowsiness.

The first three come from a blood test; the last two, from the clinical examination and the patient’s history.

How the score is calculated

Variable	1 point	2 points	3 points
Bilirubin (mg/dL)	less than 2	2 to 3	more than 3
Albumin (g/dL)	more than 3.5	2.8 to 3.5	less than 2.8
INR	less than 1.7	1.7 to 2.3	more than 2.3
Ascites	absent	mild	moderate or tense
Encephalopathy	absent	grade 1 to 2	grade 3 to 4

In liver diseases that involve cholestasis, such as primary biliary cholangitis, the bilirubin thresholds are adjusted toward higher values.

The three classes and what they mean

The sum of the five parameters places the patient in one of three classes:

• Class A (5 to 6 points): well-compensated disease. Despite the damage, the liver still maintains its functions.
• Class B (7 to 9 points): significant functional impairment.
• Class C (10 to 15 points): decompensated disease, with major deterioration.

In the classic studies, one-year survival was estimated at close to 95% in class A, around 80% in class B and about 45% in class C. These figures are group statistics and come from older series. An individual’s prognosis depends on many personal variables the scale does not include, such as the cause of the cirrhosis, the response to treatment and the control of complications.

What is it used for in practice?

The Child-Pugh score is used mainly for three purposes:

• Estimating prognosis quickly and at the bedside, without complex calculations.
• Assessing surgical risk. It remains a reference for estimating the risk of surgery in a person with cirrhosis, which is its historical origin.
• Guiding treatment decisions, for example adjusting some medications that are metabolized in the liver, or evaluating therapies in advanced cirrhosis.

Relationship and differences with MELD

The MELD is another, more recent prognostic scale that also estimates the severity of liver disease. Both aim at the same goal, but in different ways:

• The Child-Pugh includes two clinical variables (ascites and encephalopathy) that depend in part on the judgment of the person assessing them, and uses categories (little, moderate, a lot).
• The MELD is calculated only from laboratory tests (bilirubin, INR and creatinine), in a numerical and reproducible way, which reduces subjectivity.

Because of that objectivity, MELD became the standard tool for prioritizing patients on liver transplant waiting lists. Child-Pugh, in turn, remains very useful because of its simplicity for a quick estimate of prognosis and surgical risk. They do not compete: they are complementary, and your physician will choose the most appropriate one for the situation.

See also

• Cirrhosis
• MELD
• Ascites
• Hepatic encephalopathy
• Liver transplant