Pictorial health warning labels on cigarette packaging have been proposed for the U.S., but their potential influences among populations that suffer tobacco-related health disparities are unknown.
To evaluate pictorial health warning labels, including moderation of their influences by health literacy and race.
From July 2011 to January 2012, field experiments were conducted with 981 adult smokers who were randomized to control (i.e., text-only labels, n=207) and experimental conditions (i.e., pictorial labels, n=774). The experimental condition systematically varied health warning label stimuli by health topic and image type. Linear mixed effects (LME) models estimated the influence of health warning label characteristics and participant characteristics on label ratings. Data were analyzed from January 2012 to April 2012.
Compared to text-only warning labels, pictorial warning labels were rated as more personally relevant (5.7 vs 6.8, p<0.001) and effective (5.4 vs 6.8, p<0.001), and as more credible, but only among participants with low health literacy (7.6 vs 8.2, p<0.001). Within the experimental condition, pictorial health warning labels with graphic imagery had significantly higher ratings of credibility, personal relevance, and effectiveness than imagery of human suffering and symbolic imagery. Significant interactions indicated that labels with graphic imagery produced minimal differences in ratings across racial groups and levels of health literacy, whereas other imagery produced greater group differences.
Pictorial health warning labels with graphic images have the most-pronounced short-term impacts on adult smokers, including smokers from groups that have in the past been hard to reach.