title: [Cigarette smoking among adolescents. Estimated prevalence by a questionnaire and serum cotinine].
abstract: BACKGROUND
  The tobacco smoking epidemic is causing more deaths than anyone before. Young population is the main aim of tobacco advertisements. We estimated the prevalence of tobacco use among adolescents and their environment, the agreement of questionnaire and serum cotinine and the total prevalence of exposure (active plus pasive).
  
  
  METHODS
  Cross-sectional study in 439 highschool students. We obtained a blood sample and anonimously inquired about their tobacco consumption and the existence of smokers in their environment. We analized the agreement between both methods.
  
  
  RESULTS
  56% have ever smoked tobacco. Declared prevalence of consumption was 34% (CI95%= 29.49-38.51), being 40% among girls and 23% among boys. The agreement between cotinine and declaration was high only in voluntary smokers (Kappa = 0.68 for 1 o more cigarettes/day and Kappa = 0.76 for 10 or more cigarettes/day). Smoking prevalence of the famliy, friends and school among smokers was higher (80%, 71% and 88%, respectively) than among non smokers (65%, 24% and 78%). Combining questionnaire and cotinine it was estimated that total prevalence of exposure was larger than 64%.
  
  
  CONCLUSIONS
  The high prevalence of exposure and the asociation of tobacco smoking among adolescents and their environment demands an educational program against tobacco including family, social and school environments. The agreement between declaration and serum cotinine is high only when consumption is daily.
authors.affiliation: Unidad de Investigación del Hospital de la Candelaria y Atención Primaria, Santa Cruz de Tenerife, 38010, España. acabrera@hcan.rcanaria.es
authors.forename: A
authors.initials: A
authors.lastname: Cabrera de León
authors.forename: D
authors.initials: D
authors.lastname: Almeida González
authors.forename: L
authors.initials: L
authors.lastname: Pérez Méndez
authors.forename: L
authors.initials: L
authors.lastname: Carrillo Fernández
authors.forename: M
authors.initials: M
authors.lastname: Cueto Serrano
authors.forename: E
authors.initials: E
authors.lastname: Real Valcárcel
authors.forename: C
authors.initials: C
authors.lastname: Borges Álamo
authors.lastname: Navarro Brito E
mesh_terms: D000293:Adolescent; D003367:Cotinine / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012907:Smoking / Q000097:blood* / Q000453:epidemiology*; D011795:Surveys and Questionnaires
chemical_list: D003367:Cotinine