Transdermal alcohol concentration data collected during a contingency management program to reduce at-risk drinking

Abstract

Background: Recently, we demonstrated that transdermal alcohol monitors could be used in a contingency management procedure to reduce problematic drinking; the frequency of self-reported heavy/moderate drinking days decreased and days of no to low drinking increased. These effects persisted for three months after intervention. In the current report, we used the transdermal alcohol concentration (TAC) data collected prior to and during the contingency management procedure to provide a detailed characterization of objectively measured alcohol use.

Methods: Drinkers (n=80) who frequently engaged in risky drinking behaviors were recruited and participated in three study phases: a 4-week Observation phase where participants drank as usual; a 12-week Contingency Management phase where participants received $50 each week when TAC did not exceed 0.03g/dl; and a 3-month Follow-up phase where self-reported alcohol consumption was monitored. Transdermal monitors were worn during the first two phases, where each week they recived $105 for visiting the clinic and wearing the monitor. Outcomes focused on using TAC data to objectively characterize drinking and were used to classify drinking levels as either no, low, moderate, or heavy drinking as a function of weeks and day of week.

Results: Compared to the Observation phase, TAC data indicated that episodes of heavy drinking days during the Contingency Management phase were reduced and episodes of no drinking and low to moderate drinking increased.

Conclusions: These results lend further support for linking transdermal alcohol monitoring with contingency management interventions. Collectively, studies to date indicate that interventions like these may be useful for both abstinence and moderation-based programs.

Keywords: Alcohol; Alcohol detection; Harm reduction; Transdermal alcohol monitoring.

Fig. 1

Percent of participants meeting weekly contingency criteria (TAC < .03 g/dl) for both the Observation and Contingency Management phases.

Fig. 2

Average percent of days per week with No Drinking (white diamonds), Low Drinking (white circles), Moderate Drinking (grey triangles), and Heavy Drinking (black squares) for the Observation and Contingency Management phases.

Fig. 3

Average percent days (by day of the week) that participants had (a) any drinking (pkTAC > 0) and (b) heavy drinking (eBrAC ≥ 0.08%) for both the Observation (black squares) and Contingency Management (white circles) phases.

Fig. 4

Average number of self-reported standard drinks when participants met (white circles) or failed (black circles) contingency criteria in both the Observation and Contingency Management phases.