Prevalence of alcohol consumption in emergency presentations: Novel approach using two biomarkers, ethanol and phosphatidylethanol

INTRODUCTION: The aim was to determine the prevalence of alcohol-related presentations to an emergency department (ED) in a major Australian hospital, through a novel surveillance approach using two biomarkers, blood ethanol and phosphatidylethanol (PEth). METHODS: Observational study using secondary testing of blood samples collected during routine clinical care of ED patients presenting to the Royal Brisbane and Women's Hospital in Queensland, Australia, between 22 January and 2 February 2021. Data were collected from 1160 patients during the 10-day study period. The main outcomes were the prevalence of acute alcohol intake, as determined by blood ethanol, and recent use over 2-4 weeks, as determined by PEth concentrations, for all ED presentations and different diagnostic groups. RESULTS: The overall prevalence for blood ethanol was 9.3% (95% confidence interval [CI] 7.8%, 11.1%), 5.3% for general medical presentations, increasing four-fold to 22.2% for injury presentations. The overall prevalence of PEth positive samples was 32.5% (95% CI 29.9%, 35.3%) and 41.4% for injury presentations. There were 263 (25.3%) cases that tested negative for acute blood ethanol but positive for PEth concentrations indicative of significant to heavy medium-term alcohol consumption. DISCUSSION AND CONCLUSIONS: This novel surveillance approach demonstrates that using blood ethanol tests in isolation significantly underestimates the prevalence of medium-term alcohol consumption in ED presentations. Prevalence of alcohol use was higher for key diagnostic groups such as injury presentations. Performing periodic measurement of both acute and medium-term alcohol consumption accurately and objectively in ED presentations, would be valuable for informing targeted public health prevention and control strategies.