FIB-4 Calculator
The FIB-4 (Fibrosis-4) index is a non-invasive score used to screen for liver fibrosis in chronic liver disease, including hepatitis B, hepatitis C, and NAFLD. It combines age, AST and ALT liver enzyme levels, and platelet count. This calculator returns your FIB-4 score instantly with the standard clinical interpretation thresholds.
FIB-4 score
Enter age, AST, ALT, and platelet count to see the FIB-4 score.
Interpretation of FIB-4 Score:
- Less than 1.45: Low probability of advanced fibrosis
- Between 1.45 and 3.25: Intermediate probability, further assessment recommended
- Greater than 3.25: High probability of advanced fibrosis
Note: FIB-4 is a screening tool and not a definitive diagnostic test. Results should be interpreted by a healthcare professional.
How to calculate a FIB-4 score
- Enter the patient's age in years.
- Enter the AST and ALT values (U/L) from a recent blood panel.
- Enter the platelet count (10⁹/L).
- Read the FIB-4 score: below 1.45 suggests minimal fibrosis, above 3.25 suggests advanced fibrosis, and values between are indeterminate.
Frequently Asked Questions
What is the FIB-4 score?
The FIB-4 (Fibrosis-4) score is a non-invasive assessment tool that helps evaluate the degree of liver fibrosis in patients with chronic liver diseases, particularly hepatitis B, hepatitis C, and non-alcoholic fatty liver disease (NAFLD). It uses a combination of age, AST and ALT levels (liver enzymes), and platelet count.
How is the FIB-4 score interpreted?
Generally, a FIB-4 score less than 1.45 has a high negative predictive value and suggests no/minimal fibrosis. A score greater than 3.25 has a high positive predictive value for advanced fibrosis. Scores between 1.45-3.25 are indeterminate and may require additional testing.
Is the FIB-4 score a definitive diagnosis?
No, FIB-4 is a screening tool, not a diagnostic test. While it can help identify patients who may have advanced fibrosis, it cannot replace other diagnostic procedures like liver biopsy or elastography for a definitive diagnosis. Always consult with a healthcare provider for interpretation and further evaluation.
What are the advantages of using FIB-4?
FIB-4 is non-invasive, inexpensive, and uses commonly available laboratory results. It can help prioritize patients who need more intensive evaluation, reduce unnecessary procedures for low-risk patients, and monitor fibrosis progression over time without repeated invasive testing.
What other non-invasive tests are used to assess liver fibrosis?
Other non-invasive tests include APRI (AST to Platelet Ratio Index), FibroScan (transient elastography), FibroTest/FibroSure, and MR elastography. Each has its own advantages and limitations. Your healthcare provider may use a combination of these tests for a more comprehensive assessment.
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