A Real-World Experience Utilizing the FAST Score to Identify Patients With Nonalcoholic Steatohepatitis Fibrosis

We aimed to test the performance of the Fibroscan-aspartate aminotransferase (FAST) score, a noninvasive test, to identify nonalcoholic steatohepatitis (NASH) and significant fibrosis (NASH + ≥F2) in a cohort of patients with a histological diagnosis of NASH, using a cutoff of ≥0.35 as a rule in factor. We also compared performance to liver stiffness measurement (LSM) ≥8 kPa and the fibrosis-4 index (FIB-4) ≥1.3 and attempted to identify risk factors to develop a model for improving diagnostic accuracy.

Patients with histologically confirmed NASH were identified from 2020-2021. Demographic information, laboratory data, and LSM were collected. The FAST score and FIB-4 were calculated. Univariate and backward entry multivariate logistic regression analyses were performed to identify risk factors in addition to the FAST score ≥0.35 that are associated with an accurate histological diagnosis of NASH + ≥F2. Discrimination and overall accuracy were assessed using area under receiver operating characteristic curves.

Using a rule in cutoff of ≥0.35, the FAST score performed with a sensitivity, specificity, negative predictive value, and positive predictive value of 96.4%, 36.8%, 77.7%, and 81.8%, respectively. Age (P = .05) and FAST ≥0.35 (P = .001) correctly identified histologically confirmed NASH + ≥F2. The FAST + age model outperformed FAST ≥0.35 (0.70, confidence interval [CI]: 0.55-0.84), LSM ≥8 kPa (0.72, CI: 0.59-0.85), and FIB-4 ≥1.3 (0.73, CI: 0.59-0.87) with a c-statistic of 0.78 (CI: 0.64-0.92).

A FAST score with a rule cutoff of ≥0.35 performed well (c-statistic: 0.70) and was superior to LSM and FIB-4 when age was incorporated into the model (0.78) in detecting NASH + ≥F2 fibrosis in the real world.