Table 3 shows associations between demographic and lifestyle factors and 2 other measures of risky vehicle behaviors: (1) driving after using marijuana or any other illicit drug or riding after the driver used marijuana or any other illicit drug and (2) driving after using marijuana or any other illicit drug or after having 5 or more drinks or riding after the driver had used marijuana or any other illicit drug or had 5 or more drinks. The table shows 2-week prevalence measures. After adjustment for other demographic and lifestyle factors, gender was not significantly associated with these measures. Average parental education had a somewhat curvilinear association. Number of parents was related: students living with neither of their parents were more likely to report both behaviors. African American students were more likely to report both behaviors, but the difference was significant only for drug and not for drug or alcohol use. Lifestyle factors related similarly to the behaviors reported in Table 2, generally significantly. (We selected the 2 measures shown in Table 3 as being of most interest; other possible measures, e.g., driving after using marijuana or other illicit drugs, are not shown because of space limitations.)
By contrast with demographic factors, lifestyle factors were strongly associated with driving after marijuana use. Grades, truancy, evenings out, religious commitment, hours worked, and miles driven all had significant unadjusted ORs, with associations in the direction that would be expected with deviant or risky behavior. Most of the associations remained significant in the multivariate analyses, with the exception of hours worked per week, which became nonsignificant.
The associations between demographic and lifestyle factors and driving after heavy drinking were generally similar to those for driving after marijuana use. One exception was that the AOR for African Americans was not significant; that is, African American students were significantly more likely than White students to report driving after smoking marijuana but not after having 5 or more drinks. The associations for religious commitment and grade point average were in the same direction for driving after both marijuana use and heavy drinking but were distinctly stronger for marijuana. Associations for driving after using other illicit drugs were generally similar in pattern to those for driving after smoking marijuana, although with fewer AORs reaching statistical significance (data not shown).