Objective-To describe patterns of smoking in a cohort of young adults over
the first 15 months after leaving school.
Design-A four-wave, longitudinal survey design was used to gather data. Fin
al-year students from 93 schools completed the recruitment questionnaire at
an average age of 17 years. Follow-up questionnaires were posted to their
home addresses three months, nine months and 15 months after the end of sch
ool.
Setting-Victoria, Australia.
Participants-A cohort of 1903 respondents who completed and returned all fo
ur questionnaires.
Main outcome measures-Self-labelled smoking status ("heavy smoker","light S
moker", "occasional smoker", "ex-smoker", ana "non-smoker"), daily cigarett
e consumption, and maximum daily cigarette consumption.
Results-At school, 72% of the sample were "non-smokers", 5% "ex-smokers", 1
1% "Occasional", 8% "Light", and 5% "heavy smokers". At 15 months after sch
ool, these proportions had shifted to 64%, 8%, 11%, 9%, and 7%, respectivel
y. Over the study, "light smokers" and "heavy smokers" substantially increa
sed their daily consumption; "occasional" and "ex-smokers" did not. There w
as relatively high stability in self-labelled smoking status at one wave an
d the next. However, over the four waves, 38% of the sample changed their s
elf-labelled smoking status, and 41% of these had been "non-smokers" at sch
ool. A reduced second-order Markov chain model was found to fit this four-w
ave behavioural sequence. Detailed description of smoking status changes re
vealed greater progression to higher levels of smoking than transition to l
ower levels.
Conclusions-There is considerable flux in smoking patterns among young adul
ts after leaving school, suggesting an opportunity to intervene with smokin
g prevention programmes at this stage of development.