These MEK162 smokers smoke on both weekends and weekdays. College student smokers in class 3 report smoking only in social contexts (i.e., hanging out with friends, in a restaurant or bar, at a party, and while drinking). These ��social smokers�� are most likely to smoke on the weekends, smoking only 3�C5 days/month and 2�C5 cigarettes on each smoking day. The prevalence for this group is 19%. An additional 26% of college student smokers are in class 4 and report smoking only 1 or 2 days in the past month and smoking one or fewer cigarettes on those days. They are unlikely to report smoking on either the weekend or the weekdays. We refer to this group of college smokers as the ��puffers.�� The final class of smokers report moderate levels of smoking but do not report smoking in any context or on any day of the week.

The prevalence for this group is only 4%. Similar to the puffers, this group does not report smoking at least sometimes in any context; however, in contrast to the puffers, their levels of smoking are more consistent with those of the moderates. Either members of this group are failing to report where and when they smoke or the survey is failing to ask about contexts in which they smoke. We refer to this group as the ��no-context�� group. Student characteristics and behaviors of the participants within each subgroup are given in Table 1. Figure 1. Patterns of smoking among past-30-day college smokers. *Class-specific means are rescaled to lie within the 0�C1 range. The lowest observed value is subtracted from the class-specific mean and then divided by the range, which is the difference .

.. To learn more about our LCA-derived subtypes of college student smokers, individuals were assigned to classes based on estimated modal posterior probabilities of class membership given their observed patterns of smoking. The estimated classification error rates were 2%, 3%, 6%, 7%, 7%, and 9% for the two-, three-, four-, five-, six-, and seven-class models, respectively. For the final five-class model with local dependence, the estimated classification error rate was 7%. The average posterior probabilities under this final model were a respectable 0.95, 0.95, 0.89, 0.91, and 0.87 among those assigned to classes 1 through 5, respectively. Class assignments were then treated as nominal outcomes and analyzed using baseline-category logistic regression modeling.

Table 2 gives the bivariate logistic regression results for looking at differences between classes. On demographics and activities, the five classes were different in year in school (p=.01), residence location (p<.01), Dacomitinib and proportion of Greek members or pledges (p<.01). For class year, students in a higher class year were associated with lower likelihood of being a puffer versus a heavy smoker (OR=0.84, 95% CI=0.72�C0.97) or a social smoker (OR=0.76, 95% CI=0.65�C0.89). Puffers also were more likely to live on-campus compared with heavy smokers (OR=2.30, 95% CI=1.62�C3.27), moderate smokers (OR=2.