Momentary effects of exposure to prosmoking media on college students' future smoking risk.

Exposure to pro-smoking media, such as to point-of-sale displays, magazine advertising, and portrayals of smoking in movies, increases smoking in adolescents (Wellman, Sugarman, DiFranza, & Winickoff, 2006) and young adults (Rigotti, Moran, & Wechsler, 2005). Cognitive social learning and decision-making theories suggest that exposure to pro-smoking media affects smoking behavior through a gradually unfolding process, whereby sequential exposures to pro-smoking media incrementally change and strengthen individuals’ risk of smoking over time, for example by gradually strengthening their smoking intentions and eroding their smoking resistance self-efficacy over time. Changes in level of smoking risk over time eventually reach a threshold or “tipping point” after which initial smoking trials begin (DiFranza et al., 2006; Heatherton & Sargent, 2009; Sargent et al., 2002; see also Austin, Chen, & Grube, 2006; Kardes, 1994). This theoretical conceptualization suggests that it is critically important to measure acute changes in smoking risk as a function of pro-smoking media exposure to obtain a more complete understanding of the hypothesized sequential process for how pro-smoking media affects smoking behavior. Understanding this process could have important implications for developing and timing interventions to prevent pro-smoking media from exerting its persuasive effects on smoking behavior. This paper reports the results of a study that utilized ecological momentary assessment (EMA; see Shiffman, 2009; Stone & Shiffman, 1994) to measure the effect of acute exposure to pro-smoking media in the “real world” on college students’ future smoking risk. Given that so few studies have focused on the effects of pro-smoking media on college students (e.g., Biener & Albers, 2004; Gilpin, White, & Pierce, 2005; Ling, Neilands, & Glatz, 2009; Ridner, Myers, Hahn, & Ciszewski, 2010; Rigotti et al., 2005; Sepe & Glantz, 2002; Song, Ling, Neilands, Glantz, 2007), significantly more research is needed in this domain of inquiry. Emerging evidence has supported the idea that exposure to pro-smoking media can engage cognitions about smoking in a way that places people at risk for future smoking. For example, exposure to movie smoking is associated with more positive expectancies about smoking and stronger identification with smokers, and these variables, in turn, predict smoking (Tickle, Hull, Sargent, Dalton, & Heatherton, 2006; Wills, Sargent, Stoolmiller, Gibbons, & Gerrard, 2008; Wills et al., 2008). However, this work has not examined acute changes in these putative cognitive mediators as a function of pro-smoking media exposure. Large scale, ecologically valid studies such as these have used global measures of pro-smoking media exposure and measured cognitive mediators of the effects of exposure either concurrently or at some later point in time. In such studies, there is a disconnect between actual exposure to pro-smoking media and measurement of acute changes in target mediators. Laboratory studies that have examined the impact of acute pro-smoking media exposure on hypothesized mediators (e.g. smoking intentions) lack ecological validity (e.g., Pechmann & Knight, 2002; Shadel, Martino, Setodji, Haviland, & Scharf, in press; Shadel, Tharp-Taylor, & Fryer, 2008). As such, there is a need for research to utilize ecologically valid studies and designs that can closely examine how exposure to pro-smoking media acutely affects future smoking risk. Exposure to pro-smoking media affects individuals differently, depending on their level of experience with smoking. Although exposure contributes to smoking initiation (Dalton et al., 2003), progression to more established smoking (Sargent et al., 2007), and serves as a “cue” to smoke for established smokers (Lochbuehler, Engels, & Scholte, 2009), the effects of pro-smoking media on the progression from never smoking to experimental smoking are stronger than the effects of pro-smoking media on the progression from experimental smoking to regular smoking (Wellman et al., 2006). These differences are thought to be a consequence of increasing engagement of processes relating to nicotine dependence as level of smoking increases (Flay, Snyder, & Petraitis, 2009; Shadel & Scharf, in press). That is, early smoking trials are thought to be governed by socio-environmental variables such as exposure to cigarette advertising and marketing whereas progression to heavier levels of smoking are thought to be governed by processes related to nicotine dependence (e.g., craving, withdrawal, cue reactivity; see Shadel et al., 2000). Differences in how ever and never smokers respond to pro-smoking media may be observed in two ways (see Hertzog & Nesselroade, 2003). First, differences in responsiveness to pro-smoking media may be observed as differences between ever and never smokers in overall mean levels of variables that index future smoking risk (e.g., smoking intentions and smoking resistance self-efficacy; Choi, Gilpin, Farkas, & Pierce, 2001; Tucker, Ellickson, & Klein, 2002; Wakefield et al., 2004) or in smoking behavior; mean level differences are the more commonly measured outcomes (see Wellman et al., 2006). Second, differences in responsiveness to pro-smoking media may be observed in the level of variability around future smoking risk between ever and never smokers; this outcome has not been investigated in this domain of inquiry. To the extent that the development of nicotine dependence resembles a developmental process (Flay et al., 2009; Shadel & Scharf, in press; Shadel et al., 2000), mean differences between individuals who have different levels of experience with smoking may only provide partial insight into underlying processes (see Hertzog & Nesselroade, 2003). Indeed, in a recent study, Hedeker and colleagues (2009) found that adolescents’ level of smoking was related both to their mean mood levels (i.e., adolescents experienced less negative affect when they smoked compared to during random prompts) and to their level of variance in mood (i.e., adolescents experienced less mood variability as their level of smoking increased). The differences in variability were taken as evidence of the development of tolerance: mood came under increasing control of smoking as levels of smoking increased, leading to less mood volatility. Extending these findings to the current context, then, never smokers would be hypothesized to demonstrate greater variance in their response to exposure to pro-smoking media whereas ever smokers would be hypothesized to demonstrate less variance. Differences in degrees of variability in future smoking risk would be expected theoretically because pro-smoking media should have more control over never smokers’ cognitions about smoking (i.e., risk of smoking as indexed by smoking intentions and smoking resistance self-efficacy) compared to ever smokers whose smoking is theorized to be controlled more by factors relating to nicotine dependence (Shadel et al., 2000). In the current study, college students carried a handheld computer with them for 21 days to record their exposures to pro-smoking media on each of those 21 days (i.e., what kind of advertising they saw, where they were exposed; see Martino, Scharf, Setodji, & Shadel, in press). They answered questions that indexed their future smoking risk immediately after each instance of exposure to pro-smoking media. They also answered these same future smoking risk questions in response to control prompts during the 21-day study period; the control prompts occurred at random moments when there was no exposure to pro-smoking media. Using a within subjects design (e.g., Shiffman et al., 2002; see Shiffman, 2009), then, we examined whether college students’ future smoking risk was higher following exposure to pro-smoking media than in response to control prompts. We also examined whether students’ smoking status moderated this effect. We expected that never smokers would respond more strongly to pro-smoking media than would ever smokers, and that this stronger response would be evidenced both by a larger difference in their mean risk of future smoking between moments of pro-smoking media exposure and control moments as well as by greater variability in their future smoking risk in response to pro-smoking media exposures compared to control moments.