Diagnostic accuracy of the Fibrosis-4 index for advanced liver fibrosis in nonalcoholic fatty liver disease with type 2 diabetes: A systematic review and meta-analysis

Abstract

Background/Aims: The Fibrosis-4 index (FIB-4) is a noninvasive test widely used to rule out advanced liver fibrosis (AF) in patients with nonalcoholic fatty liver disease (NAFLD). However, its diagnostic accuracy in NAFLD patients with type 2 diabetes mellitus (T2DM) is controversial due to the high prevalence of AF in this population. Methods: Research focusing on the diagnostic accuracy of FIB-4 for liver fibrosis as validated by liver histology in NAFLD patients with T2DM was included, and 12 studies (n=5,624) were finally included in the meta-analysis. Sensitivity, specificity, hierarchical summary receiver operating characteristic (HSROC), positive predictive values (PPVs), and negative predictive values (NPVs) at low cutoffs (1.3–1.67) and high cutoffs (2.67–3.25) for ruling in and out AF were calculated. Results: At low cutoffs, the meta-analysis revealed a sensitivity of 0.74, specificity of 0.62, and HSROC of 0.75. At high cutoffs, the analysis showed a sensitivity of 0.33, specificity of 0.92, and HSROC of 0.85, suggesting FIB-4 as useful for identifying or excluding AF. In subgroup analyses, high mean age and F3 prevalence were associated with lower sensitivity. The calculated NPV and PPV were 0.82 and 0.49 at low cutoffs, whereas the NPV was 0.28 and the PPV was 0.70 at high cutoffs. There were insufficient estimated NPVs <0.90 at a hypothesized prevalence of AF >30% at an FIB-4 cutoff range of 1.3–1.67. Conclusions: Collectively, FIB-4 has moderate diagnostic accuracy for identifying or excluding AF in NAFLD patients with T2DM, but more evidence must be accumulated due to the limited number of currently reported studies and their heterogeneity.