Hepamet Fibrosis Score in Nonalcoholic Fatty Liver Disease Patients in Mexico: Lower than Expected Positive Predictive Value

Abstract

Background: Nonalcoholic fatty liver disease (NAFLD) has been associated with different negative outcomes in the presence of advanced fibrosis. The Hepamet Fibrosis Score (HFS), a recently described noninvasive score, has shown excellent performance for the detection of advanced fibrosis. The aim of this study was to assess its performance in a Mexican population with NAFLD.

Methods: This was a retrospective cross-sectional study performed in 222 patients with biopsy-proven NAFLD, of whom 33(14%) had advanced fibrosis. We retrieved clinical data from each patient's medical record to compute the HFS, the NAFLD Fibrosis Score (NFS), and the Fibrosis-4 (FIB-4), and assess their performance.

Results: When considering the models as continuous variables, the area under the receiving operating characteristics curve of the HFS(0.758) was not different from that of the NFS(0.669, p = 0.09) or FIB-4(0.796, p = 0.1). The HFS had a sensitivity, specificity, positive and negative predictive values of 76.7% (95% CI 57.7-90.1), 90.1% (95% CI 85-93.9), 36.7% (95% CI 19.9-56.1), and 94.3% (95% CI 88.5-97.7), respectively. Indeterminate results (i.e., gray area) were more common with FIB-4 and HFS when compared with NFS [139(63%) and 122(55%) vs 80(36%), p < 0.001]. The variables that were associated with misclassification using the HFS were diabetes [OR 3.40 (95% CI 1.42-8.10), p = 0.006] and age [OR 1.06 (95% CI 1.01-1.11), p = 0.01].

Conclusion: The HFS showed sensitivity and specificity similar to that reported in the original publication; however, the positive predictive value was 36.7% at a pretest probability of 14%. The role of the HFS in prospective studies and in combination with other methods should be further explored.

Keywords: Advanced fibrosis; Cirrhosis; FIB-4; Fatty liver; Metabolic associated fatty liver disease; Metabolic syndrome; Nonalcoholic fatty liver disease fibrosis score; Nonalcoholic steatohepatitis; Significant fibrosis; Type 2 diabetes mellitus.