RESUMO
OBJECTIVE: To determine the prevalence of tobacco use among 12-18 year-olds in Biscay (Spain) and its relation with the family environment. SUBJECTS AND METHOD: We performed a cross-sectional study in 12-18 year-olds. A self-administered, anonymous questionnaire was distributed in different schools of the region selected by stratified sampling, based on the type of school (public school or subsidized private school) and on the linguistic model. The final study sample comprised 1921 students. Information was obtained on tobacco, alcohol and other drug use, as well as on family and sociodemographic characteristics. RESULTS: A total of 51.8 % of the students had used tobacco. One-third (29.9%) of the teenagers were current smokers and 50.4% were daily smokers. The mean age of first tobacco use was 13.1 +/- 1.85 years. The prevalence of tobacco use was higher in girls and increased with age until the age of 15-16 years. More than 90 % of smokers had experimented with alcohol, 86.3 % had used cannabis at some time and 11 % had used other illegal drugs. In multivariate analysis, the variables associated with a higher odds of smoking were age, female sex, available money, use of other drugs, and smoking by siblings in front of the adolescent. CONCLUSIONS: The prevalence of tobacco use among 12-18 year-olds increased in relation to female gender, age, having siblings who smoked in their presence, available money, and the use of alcohol, cannabis and other illicit drugs. Maternal and sibling disapproval of smoking may be associated with lower tobacco use among adolescents.