The second phase of the study was a 2-year follow-up interval. After completion of the laboratory phase, participants were scheduled for 8 quarterly follow-ups to assess alcohol use patterns. The main dependent measure was frequency of binge drinking, defined as the percentage of days in the past month when the participant consumed at least 5 alcoholic drinks (4 for women). Binge frequency and other drinking variables (typical quantity, frequency of any drinking, and maximum quantity) were based on the Timeline Follow-Back for the 4 previous Monday-to-Sunday weeks. At 12 and 24 months, the Alcohol Use Disorders Identification Test, the Drinker Inventory of Consequences–Recent,75 and Structured Clinical Interview for DSM-IV Axis 1 Disorders–Patient Edition modules for past-year alcohol abuse and dependence were also administered. Participants were compensated with $10 gift cards for each quarterly follow-up and $40 gift cards for the annual follow-ups. They also received $10 to $20 gift card incentives if they completed their follow-ups in a timely manner.
