Formula and Method for the Child-Pugh Score
The Child-Pugh score (also called the Child-Turcotte-Pugh score) is a well-established clinical tool for grading the severity of chronic liver disease, most commonly cirrhosis. It combines five measures — three lab values (total bilirubin, serum albumin, INR) and two clinical findings (ascites and hepatic encephalopathy) — into a single score used to estimate prognosis, guide treatment decisions, and assess surgical risk. Each component is scored 1, 2, or 3 points based on standard cutoffs, and the five scores are added together for a total between 5 and 15 points. This is an educational calculation, not a diagnosis; use it alongside — not instead of — evaluation by a physician or hepatologist.
How the scoring works
Each of the five components is assigned points using these standard thresholds:
- Total bilirubin: 1 point if <2 mg/dL (<34 µmol/L), 2 points if 2-3 mg/dL (34-50 µmol/L), 3 points if >3 mg/dL (>50 µmol/L).
- Serum albumin: 1 point if >3.5 g/dL (>35 g/L), 2 points if 2.8-3.5 g/dL (28-35 g/L), 3 points if <2.8 g/dL (<28 g/L).
- INR: 1 point if <1.7, 2 points if 1.7-2.3, 3 points if >2.3 (the original score used prothrombin time prolongation in seconds; INR is the modern standard substitute).
- Ascites: 1 point if absent, 2 points if mild and diuretic-controlled, 3 points if moderate-to-severe or refractory.
- Hepatic encephalopathy: 1 point if absent, 2 points for grade I-II (mild, intermittent), 3 points for grade III-IV (severe, persistent).
The five component scores are summed for a total Child-Pugh score, which maps to a class: Class A (5-6 points), Class B (7-9 points), or Class C (10-15 points). Commonly cited reference survival figures associate Class A with roughly 100% 1-year and 85% 2-year survival, Class B with roughly 80% 1-year and 60% 2-year survival, and Class C with roughly 45% 1-year and 35% 2-year survival — these are population-level historical estimates, not a prediction for any individual patient.
Clinical uses and limitations
The Child-Pugh class is used to grade cirrhosis severity, estimate operative risk (higher classes carry substantially higher perioperative mortality), guide decisions about variceal bleeding prophylaxis and hepatocellular carcinoma treatment eligibility, and, historically, prioritize liver transplant referral (the MELD score has since become the primary transplant-allocation tool in many countries, but Child-Pugh remains widely used at the bedside). The score does not account for kidney function, sodium, or several other factors that affect outcomes in liver disease, and the ascites/encephalopathy components involve clinical judgment rather than a lab measurement, so results can vary slightly between examiners. Always confirm inputs and interpret results with a qualified clinician, especially before any treatment or surgical decision.