Assessing alcohol consumption in an era of direct alcohol markers.

Alcohol-related liver disease (ALD) and metabolic dysfunction-associated steatotic liver disease (MASLD) are the leading causes of advanced liver disease worldwide. The introduction of the steatotic liver disease (SLD) nomenclature, including MASLD, MetALD, and ALD, has increased the need for accurate assessment of alcohol consumption, as disease classification, prognosis, and management depend partly on alcohol exposure. Although structured interviews and validated questionnaires such as AUDIT and AUDIT-C remain standard tools, self-reported alcohol intake is limited by recall bias, underreporting, and variability in drinking patterns. This has led to growing interest in direct alcohol biomarkers that objectively reflect recent alcohol exposure. In this review, we summarise current knowledge on direct alcohol biomarkers, with particular focus on phosphatidylethanol (PEth), the most widely used alcohol marker in hepatology. We conclude that PEth provides a robust and clinically useful measure of recent alcohol consumption, but that its interpretation is influenced by biological variability and context. Importantly, currently used cut-offs are not firmly anchored to clinical outcomes and should not be applied mechanically to classify SLD subtypes. Instead, biomarker-derived measures and self-reported alcohol use should be regarded as complementary tools, best integrated in a longitudinal and clinically contextualised assessment of alcohol exposure.