title: Smoking family, secondhand smoke exposure at home, and nicotine addiction among adolescent smokers.
abstract: BACKGROUND
  Smoking family predicts adolescent smoking, but whether the level of nicotine addiction is affected by exposure to secondhand smoke (SHS) is unclear. We investigated the associations of smoking family and SHS exposure at home with morning smoking and heavier smoking among Chinese adolescent smokers.
  
  
  METHODS
  In a school-based anonymous survey, 2182 adolescent smokers reported their smoking behaviors, smoking status of family members and peers, and SHS exposure at home and outside home in the past 7 days. Families with one or more smoking members (excluding the subject) were classified as smoking families and otherwise as non-smoking families. Smoking or wanting to smoke first thing in the morning (morning smoking), and consuming more cigarettes (heavier smoking) denoted higher levels of nicotine addiction. Regression analysis yielded adjusted odds ratios (AORs) for morning smoking and β-coefficients for heavier smoking adjusting for potential confounders.
  
  
  RESULTS
  Living with siblings and other co-residing family members who smoked was significantly associated with morning smoking and heavier smoking. Compared with non-smoking families without SHS exposure at home, the AORs (95% CI) for morning smoking were 0.99 (0.76 to 1.29) for 0 day/week, 1.19 (0.95 to 1.50) for 1-3 days/week, 1.76 (1.41 to 2.21) for 4-7 days/week (p for trend <0.001) and 1.50 (1.23 to 1.83) for any days/week of SHS exposure at home in smoking families. Similarly, 4-6 days/week of SHS exposure at home significantly predicted heavier smoking.
  
  
  CONCLUSIONS
  Living with smoking family members and SHS exposure at home are associated with nicotine addiction in Chinese adolescent smokers.
authors.affiliation: School of Public Health, The University of Hong Kong, Hong Kong.
authors.forename: Man-Ping
authors.initials: MP
authors.lastname: Wang
authors.forename: Sai-Yin
authors.initials: SY
authors.lastname: Ho
authors.forename: Wing-Sze
authors.initials: WS
authors.lastname: Lo
authors.forename: Tai-Hing
authors.initials: TH
authors.lastname: Lam
mesh_terms: D000293:Adolescent; D044466:Asian People / Q000706:statistics & numerical data; D005190:Family; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D012907:Smoking / Q000453:epidemiology*; D012931:Social Environment; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000706:statistics & numerical data*; D014029:Tobacco Use Disorder / Q000453:epidemiology*
chemical_list: D014028:Tobacco Smoke Pollution