Accuracy of the FIB-4 and LiverRisk score for use in primary risk assessment for liver fibrosis, and variation by age

Background Primary risk assessment for liver fibrosis involves the Fibrosis-4 (FIB-4) index, a non-invasive test (NIT) reported to have suboptimal accuracy with lower prevalence of fibrosis, particularly at younger ages. The LiverRisk score (LRS) is a NIT developed for general-population prediction of liver fibrosis and liver-related outcomes. Aims This retrospective study compared in a general-population cohort the accuracy by age groups of the LRS vs. FIB-4 for classification of LSM ≥8 and ≥10 kPa. Methods Analysis was conducted of the National Health and Nutrition Examination Survey (NHANES) 2017–2023 cycles. Accuracy of the LRS vs. FIB-4 for classification of LSM ≥8 kPa and ≥10 kPa was evaluated as area-under-the-curve (AUC), overall, by three age groups, and by metabolic risk factors. Results The study included N = 12,050 participants. For LSM ≥8 kPa ( n = 1310), AUC (95% confidence interval) for the LRS ranged from 0.662 (0.614–0.710) at ages 18–34 to 0.711 (0.689–0.731) at ages 35–64, and for FIB-4 from 0.510 (0.462–0.559) to 0.591 (0.567–0.614) (respectively). The LRS also demonstrated improved accuracy vs. FIB-4 for LSM ≥10 kPa ( n = 724) in the age groups assessed. Conclusion In this general-population cohort, the LRS demonstrated greater accuracy vs. FIB-4 for LSM ≥8 and ≥10 kPa, particularly at younger ages.