BACKGROUND & AIMS Nonalcoholic fatty liver disease (NAFLD) includes a wide spectrum of heterogeneous metabolic subtypes. This study compared the diagnostic performances of noninvasive fibrosis tests in predicting advanced fibrosis among patients with NAFLD and examined the effects of the subgroups on their diagnostic performances.

METHODS Three hundred fifteen patients with biopsy-proven NAFLD were prospectively enrolled. Acoustic radiation force impulse imaging (ARFI) was performed to obtain liver stiffness measurements (LSMs). The aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), aspartate aminotransferase-to-platelet ratio index (APRI), fibrosis 4 index (FIB-4), NAFLD fibrosis score (NFS) and BARD score were calculated. The diagnostic performances of noninvasive fibrosis tests were evaluated using the area under the receiver operating characteristic curve (AUROC).

RESULTS Fibrosis 4 index (FIB-4) showed the highest AUROC for advanced fibrosis (0.866; 95% CI, 0.811-0.922). AUROC subgroup analyses were performed to assess the effects of the subgroups on diagnostic performance. For patients with advanced fibrosis, the APRI, BARD, FIB-4 and NFS AUROCs were significantly different among the radiological steatosis grades. Additionally, the AUROC of ARFI tended to decrease with increasing radiological steatosis severity. FIB-4 and NFS showed significantly lower AUROCs for advanced fibrosis in obese NAFLD than in nonobese NAFLD (P = .002 and P < .001 respectively). However, only radiological steatosis severity was independently associated with advanced fibrosis in multivariable analysis.

CONCLUSIONS Steatosis severity may affect the diagnostic performances of noninvasive fibrosis tests in patients with NAFLD. The application of different tools should be tailored for various NAFLD subgroups to optimize noninvasive fibrosis assessments.