Impact of Implementing a “FIB‐4 First” Strategy on a Pathway for Patients With NAFLD Referred From Primary Care

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.

Sequential Combination of FIB-4 Followed by M2BPGi Enhanced Diagnostic Performance for Advanced Hepatic Fibrosis in an Average Risk Population

“…Although FIB-4 showed a high negative predictive value for advanced liver fibrosis, it does not adequately rule-in advanced fibrosis. So, several referral pathways from primary health care settings have been proposed [8,9]. Davyduke et al suggested that vibration-controlled transient elastography (VCTE) could save up to 87% of further assessments.…”

“…Both the NFS and FIB-4 scores have considerable intermediate zones (~30%), even though both estimated formulae showed good negative predictive performance [6,7]. Because of the considerable intermediate zone and low positive predictive value of the FIB-4 system, several sequential algorithms based on the FIB-4 system have been suggested [8,9].…”

Limitations of non-invasive tests for assessment of liver fibrosis

“…This staged risk-stratification model using FIB-4 and VCTE could obviate the need for up to 87% of further assessments. 144 Combining at-risk clinical characteristics (hazardous alcohol intake, elevated ALT, metabolic risk factors) with serum markers and VCTE in primary care programmes yielded many more diagnoses of advanced liver disease in patients with alcoholrelated liver disease or NAFLD. 145,146 These combined approaches are important, but require validation based on disease aetiology, ethnicity and prevalence, as well as consideration of regional socioeconomic limitations due to differing healthcare payor systems, access to US elastography, and specialist care.…”

Cost Saving or Cost Effective? Unanswered Questions in the Screening of Patients With Nonalcoholic Fatty Liver Disease

“…Addressing this gap, Davyduke and colleagues leveraged an NAFLD referral program within the catchment of the University of Alberta to compare a two‐stage approach with the existing single‐step VCTE‐based strategy. Specifically, they evaluated 560 patients between 16‐65 years of age with elevated alanine aminotransferase or steatosis on imaging who underwent VCTE on referral.…”