The veracity of self-reported AO/AI was evaluated for participants who initiated alcohol use and/or heavy drinking during the course of the study. An empirical AO and AI were derived for each participant by noting his/her age at the assessment point during which he/she first reported alcohol use or intoxication, respectively. Of the 424 participants who reported an AO of 18 years or older, 363 (85.61%) reported a consistent AO. Most errors of estimation were underestimates (10.1% reporting an earlier AO than indicated by self-reports of drinking). Among the 665 participants who reported an AI at age 18 years or older, 68.72% of participants reported consistent AIs. As with AO, most errors were underestimates; 23.15% reported an AI that occurred earlier than was indicated by self-report. In summary, retrospective reports of AO and AI were relatively consistent with self-reported drinking.
