In terms of current alcohol and tobacco use patterns among the adolescent participants, 1120 (41.0%) adolescents used neither alcohol nor tobacco, 82 used tobacco only (3.0%), 974 used alcohol only (35.6%), and 557 (20.4%) used both substances. Analyses indicated differences in age, grade in school, median grades in classes, ethnicity and parental tobacco use between participants in the four use groups. Users of both substances appeared to be older, more likely to be female, of higher incomes, and Caucasian than users of either substance. Given the potential confounding influence of these differences, all analyses controlled for age and median academic performance. Grade in school was not controlled for, given its correspondence to age and ethnicity was not controlled for due to the difficulty in accounting for membership in multiple racial or ethnic groups. These data are summarized in Table 2.
