Using FIB-4 index first to screen for cirrhosis may lead to clinicians missing 48% of cases, according to a recent study.
New data show that the performance of noninvasive tests (NITs) to predict liver fibrosis in metabolic dysfunction-associated steatotic liver disease (MASLD) is poor compared to vibration-controlled transient elastography (VCTE). Findings also showed that the performance of NITs was significantly affected by race and ethnicity, reported researchers in the journal Obesity.
In a large, unselected population, researchers found that using the fibrosis-4 (FIB-4) index first before VCTE—as proposed in the most recent American Association of Clinical Endocrinology (AACE) guidelines—would result in missing 56% and 48% of patients with advanced fibrosis and cirrhosis, respectively, compared with using VCTE first.
“In recent years, there has been increasing interest in finding a simple screening tool for primary care providers to identify patients at risk for clinically significant liver fibrosis to target referral and/or therapeutics,” wrote coauthors Meagan Gray, MD, and Fernando Bril, MD, both of the Department of Medicine at the University of Alabama at Birmingham. “In recent guidelines, the FIB-4 index and VCTE have gained acceptance over other NITs due to their simplicity, low cost, and widespread availability.”
They continued: “However, the performance of NITs in different racial and ethnic groups had not been comprehensively assessed before, to our knowledge. Because MASLD appears to have significant differences across racial and ethnic groups, it was important to assess whether diagnostic tools performed similarly among these groups.”
Gray and Bril analyzed data from 6359 adults who participated in the National Health and Nutrition Examination Survey from 2017 to 2020 and who had blood samples and VCTE performed at the same appointment.
“Participants without valid transient elastography measurements or with alternative etiologies of liver steatosis disease were excluded from the study,” noted researchers.
For the purpose of the study, MASLD was defined as controlled attenuation parameter (CAP) ≥288 dB/m and the presence of at least 1 cardiometabolic risk factor. Advanced fibrosis was defined as a liver stiffness measurement of ≥9.7 kPa and cirrhosis was liver stiffness of ≥13.6 kPa, according to the study.
Investigators used anthropometric and laboratory measurements to calculate NIT scores—including the FIB-4 index, NAFLD fibrosis score (NFS), and aspartate aminotransferase to platelet ratio index (APRI)—as well as the fatty liver index (FLI) and NAFLD liver fat score (LFS) to estimate hepatic steatosis.
Researchers observed that the prevalence of MASLD varied by race and ethnicity, with 42% of Hispanic adults having MASLD compared to 36.8% of non-Hispanic White adults, 30.1% of Asian adults, and 26% of Black adults. In regards to the prevalence of advanced fibrosis and cirrhosis, Black and Asian adults had the lowest rates among racial-ethnic groups.
Results showed that FLI and NAFLD LFS overestimated hepatic steatosis compared with CAP across all racial groups. The overall agreement between FLI and CAP results for diagnosing hepatic steatosis was 73.4% and NAFLD LFS agreed with CAP results 73.2% of the time.
Investigators also noted that the FIB-4 index, NFS, and APRI underperformed in non-Hispanic Black participants for the detection of cirrhosis. “For the detection of advanced fibrosis, their performance was also numerically worse in non-Hispanic Black patients but only reached statistical significance for APRI,” added Gray and Bril.
In addition, researchers observed that if sequential testing was performed as proposed in the AACE guidelines (FIB-4 index first, followed by VCTE only in those with FIB-4 index score ≥1.3), clinicians would miss 56% of adults with advanced fibrosis and 48% of those with cirrhosis.
“Due to the large disagreement between the FIB-4 index and VCTE observed in this large population, a screening strategy based on the sequential use of these techniques may not be an accurate approach,” concluded Gray and Bril. “In an era of upcoming highly awaited treatment options for MASLD with fibrosis, recommended NITs for screening and treatment need to be equitable across different racial and ethnic groups. Further studies are warranted to verify these findings against liver biopsy.”
Source: Bril F, Gray M. Noninvasive tests to identify liver fibrosis in metabolic dysfunction-associated steatotic liver disease are affected by race. Obesity. Published online December 27, 2023. doi:10.1002/oby.23960