Understanding Why Pictorial Cigarette Pack Warnings Increase Quit Attempts.

Background: Our randomized trial found that pictorial cigarette pack warnings elicited more quit attempts than text-only warnings.

Purpose: In the current study, we sought to identify psychological mechanisms that explain why pictorial cigarette pack warnings change behavior.

Methods: In 2014 and 2015, we recruited 2,149 adult smokers in NC and CA, USA. We randomly assigned smokers to receive on their cigarette packs for 4 weeks either a text-only warning (one of the USA's current warnings on the side of cigarette packs) or a pictorial warning (one of the USA's proposed text warnings with pictures on the top half of the front and back of cigarette packs).

Results: Pictorial warnings increased attention to, reactions to, and social interactions about cigarette pack warnings (all p < .05). However, pictorial warnings changed almost no belief or attitude measures. Mediators of the impact of pictorial warnings included increased attention, negative affect, social interactions, thinking about the warning and harms of smoking, and intentions to quit (all p < .05). Analyses also found that pictorial warnings led to greater avoidance of the warnings, which was associated with more quit attempts (p < .05).

Conclusions: Pictorial warnings increased quit attempts by eliciting aversive reactions and by keeping the message vividly in smokers' minds. Contrary to predictions from several theories of health behavior, the warnings exerted little of their influence through changes in beliefs and attitudes and none of their influence through changes in risk perception. We propose the Tobacco Warnings Model based on these findings.

Clinical Trial information: ClinicalTrials.gov identifier: NCT02247908; https://clinicaltrials.gov/ct2/show/NCT02247908.