Health & Medicine · Clinical Scores · Renal Function
Child-Pugh Score Calculator
Calculates the Child-Pugh score to classify the severity of chronic liver disease and cirrhosis using five clinical and laboratory parameters.
Calculator
Formula
Each of the five parameters is assigned a score of 1, 2, or 3 based on severity. P_bili = points for serum bilirubin (mg/dL); P_alb = points for serum albumin (g/dL); P_INR = points for prothrombin time INR; P_asc = points for degree of ascites (none/mild/severe); P_enc = points for hepatic encephalopathy grade (none/grade I–II/grade III–IV). Total score ranges from 5 to 15. Class A = 5–6 points (well-compensated), Class B = 7–9 points (significant functional compromise), Class C = 10–15 points (decompensated).
Source: Pugh RN et al. Transection of the oesophagus for bleeding oesophageal varices. British Journal of Surgery, 1973; 60(8):646–649. Adapted from Child CG & Turcotte JG, 1964.
How it works
The Child-Pugh scoring system evaluates hepatic synthetic function and the complications of portal hypertension through five parameters: serum bilirubin (a marker of bilirubin metabolism), serum albumin (reflecting protein synthesis), prothrombin time expressed as INR (coagulation factor production), the presence and severity of ascites (fluid accumulation in the abdomen), and the grade of hepatic encephalopathy (neurological dysfunction from liver failure). Each parameter is scored on a 1–3 scale based on clinical thresholds, and the five scores are summed to produce a total between 5 and 15.
The resulting total score categorises the patient into one of three prognostic classes. Class A (5–6 points) indicates well-compensated disease with preserved hepatic function. Class B (7–9 points) represents significant functional compromise with moderate decompensation. Class C (10–15 points) signals decompensated cirrhosis with markedly impaired function and poor prognosis. These classes correspond to estimated 1-year survival rates of approximately 100%, 81%, and 45%, and 2-year survival rates of approximately 85%, 57%, and 35%, respectively, based on published cohort data.
In clinical practice, the Child-Pugh score informs surgical risk stratification — Class A patients can generally tolerate abdominal surgery, Class B patients carry moderate risk, and Class C patients face prohibitive operative mortality. The score also guides drug dosing adjustments in hepatic impairment, organ allocation prioritisation, and the decision to pursue liver transplantation evaluation. It is frequently used alongside the MELD score for a more comprehensive assessment of liver disease severity.
Worked example
Consider a patient with known cirrhosis presenting for evaluation. Laboratory results show a serum bilirubin of 2.8 mg/dL, serum albumin of 2.6 g/dL, and an INR of 2.1. Clinically, the patient has mild ascites controlled with diuretics and no hepatic encephalopathy.
Scoring each parameter: Bilirubin of 2.8 mg/dL falls between 2 and 3 mg/dL, scoring 2 points. Albumin of 2.6 g/dL is below 2.8 g/dL, scoring 3 points. INR of 2.1 falls between 1.7 and 2.3, scoring 2 points. Mild ascites scores 2 points. No encephalopathy scores 1 point.
Total Child-Pugh Score = 2 + 3 + 2 + 2 + 1 = 10 points. This places the patient in Child-Pugh Class C, indicating decompensated cirrhosis with an estimated 1-year survival of approximately 45% and a 2-year survival of approximately 35%. This result would strongly support urgent liver transplantation evaluation and cautious avoidance of elective surgery.
Limitations & notes
The Child-Pugh score has several important limitations that clinicians should recognise. The ascites and encephalopathy components are subjective clinical assessments that introduce inter-observer variability — two clinicians examining the same patient may assign different scores. The albumin and INR parameters can be influenced by factors unrelated to liver disease: malnutrition can lower albumin, and anticoagulant therapy independently elevates INR, potentially inflating the score in patients treated with warfarin. The score does not account for kidney function, which is a critical prognostic factor in advanced liver disease, a gap that the MELD score addresses. Additionally, bilirubin thresholds in the original score were validated for cholestatic liver disease (particularly primary biliary cholangitis), and may not translate equally to all aetiologies of cirrhosis. The survival estimates associated with each class are population-level averages derived from older cohorts and should never be communicated to patients as individualised predictions. For organ allocation and transplant listing decisions, current guidelines (AASLD, EASL) favour the MELD-Na score over Child-Pugh, though Child-Pugh remains valuable for surgical risk assessment and pharmacokinetic dosing guidance (e.g., FDA drug labelling categories for hepatic impairment).
Frequently asked questions
What is the difference between Child-Pugh Class A, B, and C?
Child-Pugh Class A (5–6 points) represents well-compensated cirrhosis with near-normal liver function and excellent short-term prognosis. Class B (7–9 points) indicates moderate hepatic dysfunction with clinically significant complications. Class C (10–15 points) signifies decompensated cirrhosis, associated with high morbidity, markedly reduced survival, and typically warrants liver transplantation evaluation.
How does the Child-Pugh score differ from the MELD score?
The MELD (Model for End-Stage Liver Disease) score uses serum bilirubin, creatinine, and INR in a mathematical formula derived from objective lab values only, eliminating the subjective components of Child-Pugh. MELD is currently preferred by UNOS and EASL for organ allocation due to its superior predictive accuracy. Child-Pugh, however, remains widely used for surgical risk stratification and drug dosing guidance in hepatic impairment.
Can the Child-Pugh score be used to dose medications in liver disease?
Yes. The Child-Pugh classification is frequently used by regulatory agencies including the FDA and EMA to categorise hepatic impairment in pharmacokinetic studies. Drug labels often specify dose adjustments for Child-Pugh Class A, B, or C patients. Clinicians should always check individual drug labelling, as recommendations vary significantly between agents. Class C patients typically require the most conservative dosing or complete avoidance of hepatically-metabolised drugs.
Is the Child-Pugh score valid for all types of liver disease?
The score was originally validated in patients with cirrhosis and portal hypertension, particularly those with alcoholic cirrhosis and primary biliary cholangitis. It is less well-validated for acute liver failure, non-cirrhotic portal hypertension, and paediatric liver disease. The bilirubin thresholds were originally calibrated for cholestatic disease, which may result in overestimation of severity in patients with predominantly hepatocellular disease patterns.
What surgical risk does each Child-Pugh class carry?
Child-Pugh Class A patients carry an estimated perioperative mortality of 5–10% for abdominal surgery and are generally considered acceptable surgical candidates. Class B patients face approximately 25–30% operative mortality and require careful multidisciplinary planning. Class C patients carry operative mortality estimates exceeding 80% for major abdominal procedures, and elective surgery is generally contraindicated. These estimates are derived from historical surgical series and should be interpreted in context.
Last updated: 2025-01-15 · Formula verified against primary sources.