Forns Index (HCV fibrosis)

Forns index for HCV fibrosis (Forns 2002): a four-variable serum estimate of significant fibrosis.

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Age
30 years
GGT
20 U/L
Platelet count
280 10^9/L
Total cholesterol
220 mg/dL

Result: Forns index 1.22: below 4.2 -- significant fibrosis is ruled out (negative predictive value about 96%).

The tool opens with these values already filled in. Replace them with your own.

What the result means

Thresholds
below 4.2 rules out significant fibrosis (NPV ~96%); above 6.9 rules it in; between is indeterminate.

What you enter

  • Age
  • GGT
  • Platelet count
  • Total cholesterol
How this is calculated
Formula
Forns = 7.811 - 3.131 x ln(platelets) + 0.781 x ln(GGT) + 3.467 x ln(age) - 0.014 x cholesterol (mg/dL -- the coefficient is calibrated to mg/dL, not mmol/L).

Forns X, Ampurdanes S, Llovet JM, et al. Identification of chronic hepatitis C patients without hepatic fibrosis by a simple predictive model. Hepatology. 2002;36(4 Pt 1):986-992. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.