Non-invasive Tests for Liver Fibrosis in NAFLD: Creating Pathways Between Primary Healthcare and Liver Clinics

Despite affecting around one-fourth of the general population worldwide, non-alcoholic fatty liver disease (NAFLD) remains a largely under-recognized disease in primary healthcare, with not more than 10% of patients diagnosed with NAFLD referred to specialists. The main challenge in clinical practice is the identification of those with advanced liver fibrosis or cirrhosis, as they are at the greatest risk of developing complications. Liver biopsy appears to be an unrealistic and unsuitable option because of the large number of high-risk patients and the well-known limitations of this technique. This has favoured the development of non-invasive tests, which have been an area of intensive research in the past decade. Transient elastography, FIB-4 and the NAFLD fibrosis score are the most extensively used and best validated tests, with summary AUROC values for detecting advanced fibrosis in NAFLD patients of 0.88, 0.84 and 0.84 respectively. Although much work remains to be done to establish cost-effective strategies for the screening for advanced fibrosis, the sequential use of non-invasive tests (serum biomarkers, then measurement of liver stiffness using transient elastography) appears to be the most promising strategy. The next step is to establish effective pathways in primary healthcare and/or diabetes clinics where most NAFLD patients are seen, to identify those who need to be referred to liver clinics for further assessment.