Aims: This study determined the information about recent alcohol consumption obtained when urinary ethyl glucuronide (EtG) and ethyl sulfate (EtS) were introduced as a routine test in outpatient treatment programs for alcohol and drug dependence.
Patients and methods: Outpatients (21 men and 3 women) undergoing treatment for alcohol (N = 8) or drug (N = 10) dependence, or in methadone maintenance therapy (N = 6) volunteered for the study. Twice weekly in connection with return visits to the unit, patients gave a urine sample and completed an anonymous single-question form about any drinking in the past 3 days. Urinary EtG and EtS were determined by liquid chromatography-mass spectrometry.
Results: Totally, 214 urine samples (4-14 samples/patient; mean 9) and 211 self-reports were collected over a 2-8-week period. Altogether 26% of the urine samples from 12 of 24 patients tested positive for EtG (0.5-434 mg/l) and/or EtS (0.1-87 mg/l). In one patient, samples were only positive for EtS. In 21% of 211 self-reports from 11 patients, alcohol ingestion was admitted in the past 3 days. In 87% of the 211 complete cases, the self-report information agreed with the EtG/EtS results (i.e. true positives and true negatives). The highest frequency of drinking was seen in the drug-dependent group with only 20% of the patients being abstinent according to both measures. This compares with 62.5% abstinence in the alcohol-dependent group and 50% in the methadone maintenance therapy group.
Conclusion: Although based on a limited number of subjects, these results indicated that urinary EtG and EtS testing is a useful tool for objective identification of recent drinking in outpatients treated for alcohol and drug dependence.