Reduction of smoking in Dutch adolescents over the past decade and its health gains: a repeated cross-sectional study.

BACKGROUND Smoking is the main preventable lifestyle-related risk factor threatening human health. In this study, time trends in smoking behaviour between 1996 and 2005 among adolescents enrolled in secondary school were assessed. METHODS In 1996, 2001 and 2005, a survey was conducted in the south-eastern region of the Netherlands. All students in second and fourth year of secondary education (1996: n = 20 000; 2001: n = 27 500; 2005: n = 24 000) were asked to complete a questionnaire about their smoking behaviour. A simulation model was used to estimate lifetime health gains related to the observed trends. RESULTS In 1996, 2001 and 2005, the number of questionnaires analysed were 13 554 (68%), 20 767 (76%) and 17 896 (75%), respectively. The results show a decrease in 'ever smoking' as well as 'current smoking' between 1996 and 2005. Among second year high school students, current smoking prevalence decreased from 22.2% in 1996 to 8.0% in 2005 (P(trend) < 0.001). Among fourth year students, current smoking declined from 37.5% in 1996 to 22.0% in 2005 (P(trend) < 0.001). Time trends were not influenced by gender or educational level. Model projections show that if these students not take up smoking later in life, 11 500 new cases of COPD, 3400 new cases of lung cancer and 1800 new cases of myocardial infarction could be prevented for the Dutch 13-year-olds. CONCLUSION This study found that, in the past decade, smoking prevalence among adolescents has declined by almost 50%, potentially resulting in a considerable reduction in new cases of COPD or lung cancer.