THE COURSE OF EARLY SMOKING - A POPULATION-BASED COHORT STUDY OVER 3 YEARS

Aims. To examine the uptake and course of smoking in a representative adolescent cohort. Design. Six-wave cohort study. Participants. Second ary school students initially aged 14-15 years at 44 schools in the st ate of Victoria, Australia. Measurements. Computerized questionnaire i ncluding 7-day retrospective recall for tobacco use. Findings. Prevale nce rates for smoking in the past month rose from 25% to 31% and daily smoking 9% to 18% across the 3-year follow-up. Forty-five per cent of the sample smoked at some point but only 18% were daily smokers at th e end-point. High rates of short-term cessation were observed for both experimental and daily smokers, but 70% of daily smokers relapsed wit hin 12 months. Occasional smoking at the outset was the strongest pred ictor of later daily smoking and was also predictive of lower cessatio n and higher relapse rates. Parental divorce and parental daily smokin g were associated with smoking at the outset and parental smoking was strongly predictive of the course of daily smoking. In contrast, preva lence rates of smoking in a subject's school did not significantly pre dict either smoking initiation or subsequent course. Female daily smok ers were half as likely as males to cease smoking, a finding that acco unted for gender differences in smoking prevalence in this sample. Con clusions. The strength of association between occasional and later dai ly smoking indicates the importance of primary prevention but the vari ability in the early course indicates that there should be much scope for promotion of adolescent efforts to quit. Both the diminished likel ihood of smoking cessation in young women and parental influences on s moking course deserve further exploration.