Figure 1.

Proposed diagnostic algorithm to stratify patients with nonalcoholic fatty liver disease (NAFLD) according to the risk of having advanced (F ≥ 3) liver fibrosis. Diagnostic process begins by using first tier testing-nonproprietary algorithm (FIB4 or NFS) from available simple blood tests and demographic data. Those with low risk need no further testing and might be followed in primary care (general practitioners) with repeated risk assessment at 3–5 years. Those with high risk require immediate referral to secondary care (hepatologist). Patients with indeterminate risk should proceed to second-tier testing, liver stiffness measurement (LSM) by elastography, or direct blood tests for fibrosis by patented algorithms (such as ELF or FibroMeter). ELF = enhanced liver fibrosis score; EV = oesophageal varices; HCC = hepatocellular carcinoma; MetS = metabolic syndrome; NFS = nonalcoholic fatty liver disease fibrosis score; T2DM = type 2 diabetes mellitus.