Abstract
Detection of advanced fibrosis in nonalcoholic fatty liver disease (NAFLD) is essential for stratifying patients according to the risk of liver-related morbidity. Noninvasive methods such as vibration-controlled transient elastography (VCTE) and Fibrosis-4 index (FIB-4) have been recommended to identify patients for further assessment. The aim of this study was to assess the potential impact of implementing a "FIB-4 First" strategy to triage patients entering a NAFLD assessment pathway. The pathway for patients with suspected NAFLD was piloted at a tertiary liver center. Referral criteria were 16-65 years old, elevated alanine aminotransferase and/or steatosis on imaging, and absence of a previous liver diagnosis. A registered nurse risk-stratified all patients based on VCTE and FIB-4 was calculated. Potential alternative diagnoses were excluded with bloodwork. A total of 565 patients underwent risk stratification with VCTE with a 97% success rate. Ten percent had VCTE of at least 8 kPa; 560 patients had FIB-4 available for analysis and 87% had values less than 1.3. Of those with a FIB-4 of at least 1.3, 69% had a VCTE less than 8 kPa. Further modeling showed that the presence of diabetes, age, and body mass index had only a moderate impact on the association between FIB-4 and elastography values if using a FIB-4 threshold of 1.3. Conclusion: A FIB-4 threshold of 1.3 was acceptable for excluding the presence of advanced fibrosis (assessed by VCTE). A staged risk-stratification model using FIB-4 and VCTE could save up to 87% of further assessments. This model could improve accessibility by moving the initial fibrosis evaluation to the medical home and helping to prioritize patients for further specialized care.