Background and objectives: 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.
Methods: 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.
Results: 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.
Discussion and conclusions: 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.
Scientific significance: Results suggest pre-treatment EtG cutoffs equivalent to heavy and very heavy drinking predict outcomes in CM. (Am J Addict 2017;26:673-675).
Keywords: alcohol treatment; contingency management; ethyl glucuronide; predicting treatment outcomes; serious mental illness.
© 2017 American Academy of Addiction Psychiatry.