Validation and comparison of simple noninvasive models for the prediction of liver fibrosis in chronic hepatitis C.

Although it is standard procedure in the evaluation of liver diseases, biopsy is an invasive method subject to sampling error and intra or inter-observer variability. Thus, surrogate markers of liver fibrosis have been proposed, with variable availability and accuracy. Validate and compare the performance of APRI and FIB-4 as predictors of liver fibrosis in HCV patients. Cross-sectional study including patients with HCV-RNA (+) who underwent liver biopsy. Significant fibrosis was defined as METAVIR stage ≥ 2. The diagnostic performance of the models in predicting significant fibrosis were evaluated and compared by ROC curves. The study included 119 patients, mean age 43.7 ± 10.6 years and 62% males. Significant fibrosis was identified in 41 patients. The AUROCs observed were: APRI = 0.793 ± 0.047, FIB-4 = 0.811 ± 0.045 and AST/ALT = 0.661 ± 0.055 (P = 0.054 for APRI vs. AST/ALT, and P = 0.014 for FIB-4 vs. AST/ALT). Considering classic cutoffs, the PPV and NPV for APRI and FIB-4 were, respectively, 77% and 92% and 83% and 81%. Thirteen (19%) patients were misdiagnosed by APRI and 16 (18%) by FIB-4. By restricting the indication of liver biopsy to patients with intermediate values, it could have been correctly avoided in 47% and 63% of the patients with APRI and FIB-4, respectively. The models APRI and FIB-4 were superior to AST/ALT ratio in the diagnosis of significant fibrosis in chronic HCV infection. Even though the overall performance of APRI and FIB-4 was similar, a higher proportion of patients may be correctly classified by FIB-4.