A number of possible explanations for the upward shift in reported age of onset in subsequent reports of event have been proposed and may serve as a guide for improving measurement of age at first drink in retrospective studies. For example, the potential for social desirability to lead to revising alcohol use history to fit more with perceived norms (Parra et al., 2003) could be addressed by emphasizing the wide range in age at onset of alcohol use in the population when querying early drinking behaviors. Forgetting a relatively isolated first drinking event that may have been more memorable early on in drinking course or changing the definition of alcohol use onset with increasing age (Bailey et al., 1992; Engels et al., 1997) could be minimized by encouraging respondents to recall details about the context of first alcohol use such as where and with whom they were drinking.
