This measure was based on two questions. Participants were asked on their first (baseline) assessment how many times they had consumed an alcoholic drink (an entire drink, not just a sip) of any type, in their entire lives. If one or more times, the individual was coded as a 1 from their baseline wave through the last wave examined. If no previous use was reported, the individual was coded 0 at baseline. On subsequent (post baseline) assessments, participants were asked how many days out of the previous 30 they had consumed one or more alcoholic drinks. Any nonuser up to that wave who answered with a positive number was coded a 1 for that wave, and 1 thereafter. This procedure resulted in a within-person onset variable that could only increase, from 0 to 1.
