Effect of Graphic Warning Labels on Cigarette Packs on US Smokers' Cognitions and Smoking Behavior After 3 Months: A Randomized Clinical Trial.

The US Food and Drug Administration's implementation of graphic warning labels (GWLs) on cigarette packs is under challenge in US courts. To determine whether GWLs can affect US smokers' perceptions about their cigarettes or health consequences and changes in smoking behavior. This study was a randomized clinical trial of the effect of a 3-month, real-world experience of cigarettes with GWL packaging. Community recruitment was done from September 2016 through December 2019 of daily smokers from San Diego, California, aged 21 to 65 years, who were not ready to quit. Participants were randomized to purchase and receive cigarettes in 1 of 3 pack designs: GWL, blank, or standard US pack. Data analysis was performed from July 2020 to February 2021. The study manufactured GWL cigarette packs (3 versions with Australian-licensed images) and packs devoid of marketing. For 3 months, participants purchased GWL, blank, or standard US pack cigarettes that were delivered to their home. Smoking-related cognitions and behavior were queried by daily and weekly interactive text messages. Smoking behavior was self-reported before and after the intervention by 96% of randomized participants and was biochemically validated on a subsample. The study sample included 357 participants (195 women [54.6%]; mean [SD] age, 39.5 [11.9] years); 116 were randomized to the standard US pack group, 118 were randomized to the GWL pack group, and 125 were randomized to the blank pack group. Over the 3 months, participants who received the GWL packs had reduced positive perceptions of recent cigarettes smoked compared with participants who received the branded US pack (mean difference, -0.46 SD; 95% CI, -0.73 SD to -0.20 SD; P < .001). Health concerns increased in all groups, with a significant increase in the GWL group vs the US pack group (mean difference, 0.35 SD; 95% CI, 0.09 SD to 0.62 SD; P = .002). Quitting cognitions increased in all study groups, with a peak mean change of 0.60 SD for GWL participants vs 0.34 SD for US pack participants (mean difference, 0.55 SD; 95% CI, 0.28 SD to 0.81 SD; P < .001). GWL participants had slightly more cigarette abstinence periods per week than the US pack group, but the difference was not significant (adjusted odds ratio, 1.06; 95% CI, 0.99 to 1.13). At 3 months, there was no between-group difference in any smoking behavior. The blank pack group was similar to the US pack group on all measures. These findings suggest that the introduction of GWL packs appears to decrease positive perceptions of cigarettes and increase quitting cognitions in the short term. However, additional complementary tobacco control strategies may be necessary for GWL packs to be associated with reduced smoking behavior. ClinicalTrials.gov Identifier: NCT02676193.