Aims: To determine trends in the cigarette smoking behaviour of 14- and 15-year-old students in New Zealand.
Methods: Nationwide cross-sectional surveys of fourth-form students in New Zealand in 85 schools by anonymous self-administered questionnaire in 1992 and 1997. In 1992, 79% of schools and 70% of students responded; in 1997, 88% and 72%, respectively.
Results: Responses were analysed from 11,824 14- and 15 year-old fourth formers in 1992 and from 11,350 in 1997. Daily, weekly or monthly combined smoking prevalence increased by 27% (95% confidence interval (CI) 21-32), adjusting for age, sex and ethnicity, from 23.4% in 1992 to 28.5% in 1997. Daily smoking increased from 11.6% in 1992 to 15.5% in 1997 - an adjusted 37% (95% CI = 24-47) increase. The increase in daily smoking was: greater in girls (44%, 95% CI = 33-57) than boys (28%, 95% CI = 16-42), adjusting for age and ethnicity; unrelated to the socioeconomic decile of schools; and greatest in Auckland and Northland.
Conclusion: This increase in smoking is large, 27-37% over five years, of uncertain cause, affects both sexes, all regions, ethnic and socio-economic groups, and certain cigarette brands. Regular school smoking surveys and more smokefree youth venues are recommended. Addiction and nicotine absorption merit monitoring. Legislation can require disclosure of manufacturing recipes used for youth-popular cigarette brands. On 1960-97 trends it would take 100 years to reduce fourth-form smoking to 5% prevalence. The proposed gradual denicotinisation of all cigarettes would allow smoking but prevent addiction, within ten years.