Pretreatment ethyl glucuronide levels predict response to a contingency management intervention for alcohol use disorders among adults with serious mental illness.

Abstract

This study investigated if pretreatment ethyl glucuronide (EtG) levels corresponding to light (100 ng/mL), heavy (500 ng/mL), and very heavy (1,000 ng/mL) drinking predicted longest duration of alcohol abstinence (LDA) and proportion of EtG-negative urine tests in outpatients receiving a 12-week EtG-based contingency management (CM) intervention for alcohol dependence. Participants were 40 adults diagnosed with alcohol use disorders and serious mental illness who submitted up to 12 urine samples for EtG analysis during a 4-week observation period and were then randomized to 12-weeks of CM for alcohol abstinence and addiction treatment attendance. Alcohol use outcomes during CM as assessed by EtG and self-report were compared across those who did and did not attain a pre-treatment average EtG level of 500 ng/mL-a level that equates to frequent heavy drinking. Only the 500 ng/mL cutoff was associated with significant differences in LDA and proportion of EtG-negative samples during CM. Those with a pre-treatment EtG < 500 ng/mL attained a LDA 2.3 (alcohol) to 2.9 (drugs) weeks longer than pre-treatment heavy drinkers. The EtG biomarker can be used to determine who will respond to a CM intervention for alcohol use disorders and could inform future trials that are designed to be tailored to individual patients. Results suggest pre-treatment EtG cutoffs equivalent to heavy and very heavy drinking predict outcomes in CM. (Am J Addict 2017;26:673-675).