ALSPAC participants were administered a self-report questionnaire that included alcohol use items at approximately age 20.75. These items included questions about frequency of alcohol use and average number of drinks per drinking day, from which the Consumption variable is derived; DSM-IV and AUDIT (Babor et al., 2001) items, from which a problems sum score is derived; and maximum number of drinks in 24 h. Thus, they corresponded quite closely to those administered to S4S participants. Sample size varied across outcomes (Consumption N = 3,150, Problems N = 2,906, and Maxdrinks N = 2,670) as a function of attrition and alcohol use initiation.
