**Conflict of interest**

**INITIAL DIAGNOSIS OF NAFLD**

While working on the different sections of this chapter, we have detailed the fundamental elements for the development of a diagnostic algorithm and a follow-up procedure for NAFLD (**Figure 2**). This algorithm is based on clinical evidence available in the current literature with respect to the topic and on different guidelines issued by the principal international associations for the study of the liver (EASL and AASLD). In the case of monitoring and follow-up of these patients where the existing evidence is not relevant in certain aspects, our recommendations are based on the experience of our clinical group in different high-quality studies

Once the initial diagnosis of NAFLD is made, our posterior attitude will depend on the result of the non-invasive liver fibrosis methods. In general, current image techniques are quite reliable to distinguish between advanced fibrosis (≥*F*3) and mild fibrosis or null (*F*0–*F*1), but they are insufficient to identify those patients with significant fibrosis (≥*F*2). Therefore, in clinical practice, we recommend the combination of elastographic techniques with serum markers, more specifically TE and NFS due to their wide accessibility and ease of application. When these two parameters generate doubt about the grade of fibrosis or indicate possible significant fibrosis, liver biopsy is necessary. Depending on the result, we determine the posterior follow-up as can be seen in the algorithm (**Figure 2**). The presence of metabolic risk factors influences not only the therapeutic management but also the follow-up. If liver biopsy is

**Transient Elastography + NFS**

**M probe ≥ 7 kPa XL probe ≥ 6.2 kPa +/- NFS > 0.676**

> **Liver biopsy + DEMILI + OWLiver**

F0-1 F2-3 F4

follow-up. Screening for HCC

Screening for HCC. Specific management

NAFL Semi-annual

NASH

Annual follow-up

**M probe < 7 kPa XL probe < 6.2 kPa +/- NFS < -1,455**

NAFL NASH

**OWLiver**

Annual follow-up

**7. Diagnostic algorithm and follow-up**

20 Liver Research and Clinical Management

**Figure 2.** Clinical algorithm for the diagnosis of NAFLD and monitoring disease progression.

Follow-up by primary care physician. Recalculate NFS / FIB-4 every 4-5 years (every 2-3 years in paents with metabolic risk factors)

in this field.

The authors declared that they do not have anything to disclose regarding funding or conflict of interest with respect to this chapter.
