Background: Alcohol use disorders represent a major health burden. Efforts aiming at reducing alcohol-related harm include early detection of those with risky drinking habits as well detection of early relapse in patients with alcohol dependence who are detoxified and committed to abstinence. Recently, ethyl glucuronide has been proved to be a good biomarker for the detection of recent drinking. However, to date, no randomized diagnostic trial has tested its impact on drinking outcomes. The aim of this study was to assess, with a randomized design, the implications of ethyl glucuronide screening on alcohol outcomes, compared to screening with a low-sensitivity biomarker such as ethanol.

Methods: alcohol dependent outpatients were randomized to either 24 weeks of continuous screening with ethyl glucuronide or ethanol. Patients were aware of screening methods and results. After 24 weeks, all participants were screened with ethyl glucuronide. Self-reports were also gathered. A logistic regression model was performed comparing the rate of ethyl glucuronide positive results at study end between groups. Generalized estimating equations were performed to evaluate the descending rate of EtG positive patients in the EtG group, measured month to month.

Inclusion Criteria:

• subjects had to be diagnosed of alcohol dependence according to DSM-IV, they had to undergo regular urine screening as part of their treatment and be willing to give informed written consent.

Exclusion Criteria:

• conditions rendering patients unable to complete study procedures