Background The Fib-4 index is a simple and inexpensive biomarker to delineate liver fibrosis in chronic hepatitis C.
Aim To assess the accuracy of the FIB-4 index in chronic hepatitis B.
Methods We compared the FIB-4 index with 138 synchronous liver biopsies and with 372 synchronous FibroTest performed either in France or in an endemic area (Mayotte, an overseas collectivity of France).
Results The FIB-4 index allowed the correct identification of patients with nil-to-moderate fibrosis with an area under the receiving operating characteristic curve of 0.81 (P < 0.001), increasing as a function of the length of the liver biopsy (up to 0.94 for liver biopsies ≥20 mm). A cut-off value ≤1.45 differentiated moderate fibrosis from severe fibrosis with a negative predictive value of 86%, a sensitivity of 71.1% and a specificity of 73.1%. Beyond 1.45, the FIB-4 index was not informative. The FIB-4 index was more precise than the AST-to-platelet ratio index and correlated with the FibroTest in 89% of the cases (κ = 0.27, P < 0.001) to exclude severe fibrosis.
Conclusion The FIB-4 index is a simple, accurate and inexpensive method to exclude significant liver fibrosis in chronic hepatitis B, a major advantage in HBV-endemic developing countries.