Aim: To construct and evaluate a new non-invasive fibrosis index for assessment of the stage of liver fibrosis.
Methods: A new fibrosis index (Fibro-Stiffness index) was developed in 165 of 285 patients with chronic hepatitis C, and was validated in the other 120 patients where liver biopsy was performed. Its usefulness was compared with liver stiffness (LS) measured by FibroScan, the aminotransferase-to-platelet ratio index, the Forns index and the FibroIndex.
Results: The Fibro-Stiffness index consists of LS, platelet count and prothrombin time. The values of the Fibro-Stiffness index differed significantly between neighboring fibrosis stages except F0-F1. The area under the receiver operating characteristics curves of the Fibro-Stiffness index for prediction of F ≥ 2 (0.90), F ≥ 3 (0.90) and F = 4 (0.92) in the estimation group and those for F ≥ 3 (0.93) and F = 4 (0.97) in the validation group were the highest among the 5 methods examined. The accuracy of the Fibro-Stiffness index had highest values for F ≥ 2, F ≥ 3 and F = 4 in both the estimation and validation groups. The diagnostic performance for F = 4 was improved by a combination of the Fibro-Stiffness index with serum hyaluronic acid level.
Conclusion: The Fibro-Stiffness index was constructed and validated. It showed superior diagnostic performance to other indices for F ≥ 2, 3 and 4.