Measuring alcohol consumption with biomarkers in intervention studies: A scoping review

In intervention studies, alcohol consumption is often measured by self-report alone, which can be impacted by social desirability, recall, and other biases. Biomarkers and biosensors have gained popularity as objective measurements of alcohol consumption that can improve the accuracy of results. This scoping review provides a narrative overview and describes the use of biomarkers in alcohol intervention studies to inform future research. We conducted a review of alcohol intervention literature including published studies and Clinicaltrials.gov registrations (2000-2021). Randomized controlled trials, quasi-experimental, and nonexperimental studies were included if they piloted or evaluated an intervention aimed at reducing unhealthy alcohol consumption and if an alcohol biomarker was used. Data charting included type of biomarker(s), the country and context of the study location, and a description of how the biomarker was used in analysis. We identified 168 alcohol intervention studies that included at least one biomarker. Blood alcohol content was the most used (N = 76). There was an upward trend in biomarker use over time; 24% of studies were published between 2000 and 2010, and 76% between 2011 and 2021. The use of direct biomarkers, phosphatidylethanol and ethyl glucuronide, and biosensors has increased in frequency over time relative to indirect biomarkers, such as aspartate aminotransferase, carbohydrate-deficient transferrin, and alanine aminotransferase. Most studies were conducted in high-income countries; only 15% were conducted in a low- or middle-income country. More than half of completed studies did not report on comparisons between self-report and biomarker results even when both were collected. Among studies that did report a comparison, 26% reported discordance between self-report and biomarker results. The use of direct biomarkers and biosensors is accelerating. There is a need for more consistency in reporting biomarker/self-report concordance results, more comparisons between multiple biomarkers, and for greater geographic representation within the alcohol biomarker literature.