标题：Household Smoking Bans and Adolescent Antismoking Attitudes and Smoking Initiation: Findings From a Longitudinal Study of a Massachusetts Youth Cohort
摘要：Objectives. We sought to determine whether adolescents living in households in which smoking was banned were more likely to develop antismoking attitudes and less likely to progress to smoking compared with those living in households in which smoking was not banned. Methods. We completed a longitudinal 4-year, 3-wave study of a representative sample of 3834 Massachusetts youths aged 12 to 17 years at baseline; 2791 (72.8%) were reinterviewed after 2 years, and 2217 (57.8%) were reinterviewed after 4 years. We used a 3-level hierarchical linear model to analyze the effect of a household ban on antismoking attitudes and smoking behaviors. Results. The absence of a household smoking ban increased the odds that youths perceived a high prevalence of adult smoking, among both youths living with a smoker (odds ratio [OR] = 1.56; 95% confidence interval [CI] = 1.15, 2.13) and those living with nonsmokers (OR = 1.75; 95% CI = 1.29, 2.37). Among youths who lived with nonsmokers, those with no home ban were more likely to transition from nonsmoking to early experimentation (OR = 1.89; 95% CI = 1.30, 2.74) than were those with a ban. Conclusions. Home smoking bans may promote antismoking attitudes among youths and reduce progression to smoking experimentation among youths who live with nonsmokers. The proliferation of US smoke-free workplace policies and laws over the past decade has been accompanied by increased attention to private household smoking restrictions. The number of US households with comprehensive rules that make homes smoke free in all areas at all times has increased substantially. 1 The proportion of US households with smoke-free home rules increased from 43% in 1992 to 1993 to 72% in 2003. 2 Even smokers appear to be increasingly adopting such rules, particularly in homes in which they live with a nonsmoking adult. Although smoke-free home bans are typically implemented to reduce or eliminate environmental tobacco smoke exposure in the household, these bans may have the additional benefit of reducing the initiation of smoking among youths by changing norms about the prevalence and social acceptability of smoking. Very little is known about the specific effect of a household smoking ban on youth smoking behavior or on smoking-related attitudes and norms that may mediate an effect on smoking behavior. In particular, few studies have addressed the independent effect of bans on youths who live with smokers—those who are at the greatest risk for becoming smokers themselves. Recent studies showed that strong smoking regulations in local restaurants and bars were associated with more negative attitudes among youths toward the social acceptability of smoking in restaurants and bars. 3 – 6 Establishing household smoking bans conveys to youths living within these smoke-free home environments the message that smoking is unacceptable. Some supportive evidence, derived from cross-sectional data, indicates that a household smoking ban is associated with antismoking attitudes and norms. A recent cross-sectional study found that a household ban was associated with a lower perceived prevalence of adult smoking and more-negative attitudes about the social acceptability of smoking, 2 factors that affect the likelihood of smoking initiation. 7 Several cross-sectional studies have reported that a smoking ban in the household was associated with a lower likelihood of being in an earlier stage of smoking and a lower current smoking prevalence among adolescents. 8 – 11 Conversely, other studies found no statistically significant association between a household smoking ban and reduced adolescent smoking. 12 – 14 Several factors may account for these conflicting results, including varying sample sizes, age groups, and smoking measures used in these cross-sectional studies. A critical question is whether antismoking socialization occurs when parents themselves smoke. One study found that a household smoking ban was related to lower levels of smoking onset for children with nonsmoking parents but not for children with 1 or more parent who smoked. 15 Another study reported that a household smoking ban was not associated with trying smoking among high school students who had 1 or more parents who were current or former smokers. 16 Only 1 study reported an association between a household smoking ban and a reduced likelihood of smoking among 12th graders whose parents were smokers but not among those whose parents were nonsmokers. 17 In summary, more evidence supports an association between home smoking bans and lower levels of smoking behaviors among youths who live with nonsmokers. Current research on household smoking bans has significant limitations. First, these studies rely on cross-sectional data that limit the ability to indicate causality in the relation between home smoking bans and trajectories of attitudes and smoking. Second, most studies have focused on individual-level predictors of attitudes and smoking behaviors, despite evidence that part of the explanation lies within the community context. 18 Third, few studies have investigated the unique effects of a household smoking ban among adolescents living in home environments with parental smokers compared with those living with nonsmokers. In this study, our goal was to improve existing research by (1) using longitudinal data that followed up a cohort of youths and young adults who lived in parental homes over a 4-year period, with a total of 3 repeated observations for each participant; (2) using a multilevel model that simultaneously examined the effects of individual-level and town-level factors; and (3) investigating separately the effects of a household ban on youths who live with at least 1 smoker and youths who live with nonsmokers.
