Pushing Secondhand Smoke and the Tobacco Industry Outside the Social Norm to Reduce Adolescent Smoking

Tobacco control programs have often considered creation of smokefree environments and adolescent smoking prevention as two separate strategies. In this issue of Journal of Adolescent Health, Bernat, el al.¹ demonstrate that creation of smokefree environments is a highly effective adolescent smoking prevention strategy. In addition, they show that, as in young adults,² having anti-tobacco industry attitudes is a powerful deterrent to smoking. These effects are so large that they can neutralize the pro-tobacco effects of peers and parents who smoke.

Understanding adolescent smoking behavior is more complex than simply knowing whether an adolescent smokes his or her first cigarette or not. Adolescent tobacco use has been described using five stages of adolescent smoking progression (precontemplation, contemplation, initiation/tried, experimenting, and established/daily smoking)^3-8 and individual differences in ways adolescents move through these stages across time.^9-16 Bernat et al. significantly expand upon this understanding of smoking dynamics by identifying more detailed smoking trajectories that have different temporal patterns and respond differently to the adolescents' environments. In particular, they identified six different behavioral trajectories: non-smoking (no tobacco use), triers (infrequent use), occasional (intermittent use, but smokes less than once a month), early onset (established smoker by age 16), late onset (established smoker by age 18), and decliners (established smoker by age 14, but declines in use by age 17). The identification of these detailed trajectories stress the importance of moving beyond simply preventing experimentation and initiation to implementing interventions designed to move more adolescents away from smoking trajectories or on to the decliner trajectory. Several policy and attitudinal factors reduce adolescents' risk of being on a smoking trajectory, including smokefree homes, perceived difficulty of public smoking, and anti-industry attitudes.

Increased awareness of the dangers of secondhand smoke deters adolescent smoking^{17, 18} and having smokefree homes decreases adolescent smoking.^19-22 Bernat, et al. demonstrate the significant role smokefree homes plays in protecting adolescents from tobacco experimentation and continuation across time. Creating a smokefree home reduces the odds that an adolescent will try cigarettes (triers trajectory) by about half. In addition, adolescents who come from smokefree homes are significantly more likely to be nonsmokers and have reduced odds of being on a smoking trajectory of 0.20-0.52 for occasional, early onset, late onset, and decliner compared to adolescents who live in homes without such restrictions.

Policies that institute smokefree public spaces, particularly workplaces, reduce adult smoking,^{23, 24} through a combination of making it more difficult to smoke and by reducing the social acceptability of smoking.²⁵ Bernat, et al. show a similar powerful effect of perceived difficulty of finding a place to smoke for both preventing and reducing adolescent smoking. They found a 0.28-0.80 reduced odds of being on a smoking trajectory for each unit increase in perceptions of difficulty in public smoking (measured on a four point scale from very hard to not all hard). Compared to adolescents who believe public smoking is not at all hard, adolescents who perceive public smoking to be very hard are more likely to be nonsmokers than triers, with odds of being on the triers trajectory reduced by half. This effect is large enough to nearly counterbalance the influence of pro-smoking factors, such as the effect parents who smoke has on being a member of the triers trajectory over the nonsmoking trajectory (OR=2.4).

The effect of perceived difficulty of public smoking is even stronger in more advanced smoking trajectories: compared to those who perceive public smoking as very easy, adolescents who perceive public smoking as very difficult are more likely to be nonsmokers, with odds of 0.37, 0.16, 0.36, and 0.02 for being on occasional, early onset, late onset, and declining trajectories, respectively. These effect sizes are large enough to mitigate the influence of parents who smoke for adolescents on early onset smoking (OR=4.37) and late onset smoking (OR=2.22) trajectories.

Bernat, et al also add important new information that explains why undermining the social acceptability of the tobacco industry itself is a powerful intervention to reduce adolescent smoking. This approach, pioneered by California,^{26-28, 29} is a key element of several tobacco control media campaigns, most notably the American Legacy Foundation's “truth” campaign,³⁰ which has repeatedly been demonstrated to be an important and effective tool against adolescent and young adult smoking.^{2, 27, 31-41} (Perhaps the best evidence that these anti-industry messages work are the political and litigation efforts to prevent states and the American Legacy Foundation from using these messages.^{26, 29}) These campaigns contrast with industry-funded campaigns that frame the behavior of smoking as an adult choice offered by a responsible industry.⁴² Adolescent “youth smoking prevention” ads created by the tobacco industry are associated with perceptions of low tobacco-related risks, stronger approval of smoking, and a greater likelihood of smoking.^{31, 43} Bernat et al show that anti-industry messages are particularly effective in halting the progression of adolescent smoking. They show that anti-industry attitudes (measured on a 0-4 point Likert scale ranging from strongly disagree to strongly agree) are protective against membership in the occasional, early onset, late onset, and declining smoking trajectories. The odds of being a nonsmoker, compared to being in one of these later-stage smoking trajectories increases by a factor of 1.22-1.89 (depending on the trajectory) for each unit increase in anti-industry attitudes.

For example, strongly anti-industry adolescents have reduced odds of being advanced smokers, with 0.51, 0.29, 0.55, and 0.15 odds of being occasional, early onset, late onset, and declining smokers, compared to those who hold strong pro-industry attitudes. Holding strong anti-industry attitudes can counterbalance the effect of peer influence on early onset smoking. Moreover, strong anti-industry attitudes can reduce the effect of peer influence on occasional smoking by half. Increasing anti-industry attitudes is vital in curbing tobacco consumption among adolescents who have already tried smoking.

Increasing anti-tobacco industry sentiments, establishing smokefree homes, and passing laws requiring smokefree workplaces and public places are integral components to adolescent tobacco control. Many adolescent prevention and intervention efforts are geared towards communicating the health risks of smoking, an emphasis that neglects the central role social norms play in adolescent smoking. Educating adolescents on the dangers of secondhand smoke and the tobacco industry's manipulation tactics are effective tools in denormalizing smoking and moving adolescents off the various trajectories that Bernat, et al identify and back to being nonsmokers. These messages are crucial elements of any program to prevent and curb adolescent smoking.