We read with interest the article by Parkes et al in Gut1 and fully agree with the authors' aims in evaluating the performance of a non-invasive marker of fibrosis, the enhanced liver fibrosis (ELF) test, with respect to clinically meaningful end points of liver-related complications and mortality. However, we believe that the methodology used is inappropriate and has led to potentially misleading conclusions.

The authors have previously shown that ‘severe fibrosis’, i.e. stage 3 (‘bridging fibrosis’) and 4 (cirrhosis) in patients with non-alcoholic steatohepatitis is better predicted by an ELF panel score of 9.9–10.35.2 They also showed that ELF scores are not significantly different between different liver disease aetiologies. In this paper,1 they …