Smoking family, secondhand smoke exposure at home, and nicotine addiction among adolescent smokers

Introduction: 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 IS-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% Cl) 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. Conclusion: Living with smoking family members and SHS exposure at home are associated with nicotine addiction in Chinese adolescent smokers. (C) 2012 Elsevier Ltd. All rights reserved.