RESULTS
Baseline Participant
Characteristics
Participants were 1068 adolescents
(46.7% female, 92.6% white, 10.3% Hispanic)
with a mean age of 16.8 years
(Table 2). Participants smoked on average
6.7 cigarettes per day; 61.8%
were daily smokers. The sample was
moderately nicotine dependent (Modified
Fagerström Tolerance Questionnaire
mean: 4.26 [SD: 1.70]). The 2
groups were similar in sociodemographic
and smoking characteristics.
Approximately 66% of intervention
group students planned to quit within
the next 12 months compared with
57% of control students. The intervention
group had slightly higher depression
and anxiety scores.
3- and 12-Month Abstinence Rates
In unadjusted analyses, at 3 months,
10.7% of students reported abstinence
in the intervention group compared with
5.9% in the control group (P .006);
male students accounted for the difference
(Fig 2; Table 3). At 3 months, the
intervention increased the odds of
quitting (odds ratio [OR]: 1.90 [95%
confidence interval (CI): 1.12–3.24])
with the effect limited to boys. This
gender effect remained after adjusting
for baseline differences in depression
and anxiety. There were no significant
differences in self-reported quit rates
between conditions at 12 months. In
analyses of cotinine-confirmed abstinence
with and without imputation for
missing cotinine values, quit rates
were lower but the conclusions were
the same: an intervention effect was
evident only for male students at 3
months.
Effect on Smoking Frequency
The intervention was associated with a
reduction in the number of cigarettes
smoked and the number of days
smoked in the past 7 days at 3-month