Mixed-methods trial of a phosphatidylethanol-based contingency management intervention to initiate and maintain alcohol abstinence in formerly homeless adults with alcohol use disorders.

Background: Contingency management (CM) is an intervention where incentives are provided in exchange for biochemically confirmed alcohol abstinence. CM is effective at initiating alcohol abstinence, but it is less effective at maintaining long-term abstinence. Phosphatidylethanol (PEth), collected via a finger-stick, can detect alcohol use for 14-28 days. PEth allows for the development of a CM model that includes increasingly less frequent monitoring of abstinence to assist high risk groups, such as formerly homeless individuals, maintain long-term abstinence.

Aims: Investigate whether PEth-based CM intervention targeting alcohol abstinence in formerly homeless, currently housed individuals with alcohol use disorders is: (1) acceptable and feasible for housing program tenants and personnel; and is associated with increased (2) alcohol abstinence and (3) housing tenure.

Methods: Acceptability and feasibility will be assessed using a QUAL+quant mixed-methods design using qualitative interviews and quantitative measures of satisfaction and attrition. Effectiveness will be evaluated through a randomized pilot trial of 50 study participants who will receive 6 months of either treatment as usual (TAU) including incentives (e.g., gift cards) for providing blood samples (Control Condition) or TAU and incentives for negative PEth results (PEth-CM Condition). Outcomes will be assessed during the intervention and at a three-month follow-up visit. The trial will be conducted via telehealth as a result of COVID-19.

Discussion: This protocol seeks to utilize a novel alcohol biomarker to evaluate the acceptability, feasibility, and initial effectiveness of a CM model that encourages long-term abstinence in a high-risk group.