The Daily Drinking Questionnaire-Revised (DDQ-R) was used to obtain estimates of drinks per drinking day and drinks per week. The DDQ-R, adapted from the original DDQ (Collins et al., 1985), assesses typical drinking behavior in the prior three months through the use of two questions: 1) for each day of the week, participants were asked to report the number of times in the prior 13 weeks they had consumed any alcohol and 2) on a typical day of the week in which drinking took place, they reported the number of standard drinks they typically consumed. Drinks per drinking day was calculated by taking the mean number of drinks per day for each day of the week, weighted according to how many of these days out of the prior 13 the participant reported consuming alcohol.
