The Performance of Alcohol Markers Including Ethyl Glucuronide and Ethyl Sulphate to Detect Alcohol Use in Clients in a Community Alcohol Treatment Programme

Aims: The ethanol metabolites ethyl glucuronide (EtG) and ethyl sulphate (EtS) are detectable for longer in urine than breath ethanol or urine ethanol after alcohol intake. This study compared the performance of breath ethanol, urine ethanol, urine EtG and EtS to detect alcohol consumption in clients in community alcohol treatment. Methods: Clients attending the community alcohol treatment programme were asked to provide an alcohol diary, breathalyser test and urine for ethanol, EtG and EtS measurement (n = 42). Positive results were defined using the detection limits (breath ethanol and urine ethanol) or clinical cut-offs (EtG: 0.26 mg/L and EtS: 0.22 mg/L). The sensitivities and specificities of each marker to detect alcohol intake <24 and 48-72 h prior were calculated. Results: The sensitivities of each alcohol marker to detect alcohol intake <24 h prior were 57, 71, 100 and 100% for breath ethanol, urine ethanol, urine EtG and urine EtS, respectively. The specificity was 100% for urine ethanol and urine EtS. The EtG specificity could be increased to 100% by using a higher cut-off (0.50 mg/L). The sensitivity of all markers (including EtG and EtS) to detect alcohol intake of <= 10 units 48-72 h earlier decreased to 0%. Conclusions: In community alcohol treatment clients, urine EtG and EtS showed the optimum diagnostic performance to detect alcohol intake in the previous 24 h. We propose a flowchart to routinely use EtG and EtS for clients in community alcohol treatment. Short summary: The ability of breath ethanol, urine ethanol, urine EtG and urine EtS to detect continued alcohol consumption in clients in community alcohol treatment were compared. Urine EtG and EtS showed the optimum diagnostic performance and we propose a flowchart to routinely use EtG and EtS in community alcohol treatment.