Non-alcoholic fatty liver disease (NAFLD) is the leading cause of long-term liver damage worldwide, with an estimated prevalence of 25%, and is generally associated with metabolic risk factors such as obesity, diabetes and dyslipidaemia.1, 2, 3, 4, 5 Non-alcoholic hepatic steatosis (NASH), with a prevalence of 3–5%,5 is an advanced stage of NAFLD characterised by intrahepatic fat accumulation and a pro-inflammatory state. It is in these NASH patients where we find the most advanced stages of fibrosis (approximately 20% with advanced fibrosis [F3–F4]),6, 7, 8, 9 which leads to end-stage liver disease, hepatocellular carcinoma and can even lead to liver transplantation or death.10

Establishing the epidemiological characteristics of NASH is therefore extremely important. However, the results of epidemiological studies published to date are very limited and diverse, probably due to the large variability in the populations studied and in the way the disease is managed.5, 11, 12, 13 A recent nationwide study provides somewhat more reliable estimates of the epidemiology in the Spanish population, with prevalences of patients with NASH stage F2-F3 and cirrhosis of 1.33% (95% confidence interval [CI]: 0.29–5.98 %) and 0.70% (95% CI: 0.10–4.95 %) respectively.14 It is important to highlight that, although for the management of patients with NASH, the "gold standard" diagnostic technique is liver biopsy, this is associated with major ethical, practical and safety dilemmas in routine clinical practice, and its use therefore tends to be avoided.15 A number of national and international consensus documents have been published on the management of patients with NASH,4, 13, 16, 17, 18 but it is not known to what extent these guidelines are followed in routine clinical practice.

The Delphi technique is a qualitative research method based on obtaining expert opinions on a real clinical practice problem. The technique allows consensus to be reached or the reality of a particular clinical problem to be described through anonymous group interaction based on a series of consultation meetings. Experts can reconsider their views based on the contribution of others, thus allowing for an element of reflection not found in studies based on individual interviews.19, 20

In summary, this is a disease with a high incidence and prevalence, in which patient management is not fully optimised. Knowledge of the current situation involving patients with NASH in Spain could therefore help provide healthcare professionals with a better understanding of the disease, while identifying the main needs, improving patient management, and helping healthcare systems to make informed decisions at a time of increasing financial and structural pressure. The aim of this study was to depict the epidemiology of the disease at a national level, describe the clinical management (including diagnosis and follow-up of patients), identify the therapeutic approach to these subjects, assess the impact on quality of life and describe the main unmet needs of NASH-associated F3-F4 fibrosis, based on the opinion and practical experience of and available data from Spanish physicians treating these patients.