Effect of Pictorial Cigarette Pack Warnings on Changes in Smoking Behavior: A Randomized Clinical Trial.
OBJECTIVE
Pictorial warnings on cigarette packs draw attention and increase quit intentions, but their effect on smoking behavior remains uncertain.


OBJECTIVE
To assess the effect of adding pictorial warnings to the front and back of cigarette packs.


METHODS
This 4-week between-participant randomized clinical trial was carried out in California and North Carolina. We recruited a convenience sample of adult cigarette smokers from the general population beginning September 2014 through August 2015. Of 2149 smokers who enrolled, 88% completed the trial. No participants withdrew owing to adverse events.


METHODS
We randomly assigned participants to receive on their cigarette packs for 4 weeks either text-only warnings (one of the Surgeon General's warnings currently in use in the United States on the side of the cigarette packs) or pictorial warnings (one of the Family Smoking Prevention and Tobacco Control Act's required text warnings and pictures that showed harms of smoking on the top half of the front and back of the cigarette packs).


METHODS
The primary trial outcome was attempting to quit smoking during the study. We hypothesized that smokers randomized to receive pictorial warnings would be more likely to report a quit attempt during the study than smokers randomized to receive a text-only Surgeon General's warning.


RESULTS
Of the 2149 participants who began the trial (1039 men, 1060 women, and 34 transgender people; mean [SD] age, 39.7 [13.4] years for text-only warning, 39.8 [13.7] for pictorial warnings), 1901 completed it. In intent-to-treat analyses (n = 2149), smokers whose packs had pictorial warnings were more likely than those whose packs had text-only warnings to attempt to quit smoking during the 4-week trial (40% vs 34%; odds ratio [OR], 1.29; 95% CI, 1.09-1.54). The findings did not differ across any demographic groups. Having quit smoking for at least the 7 days prior to the end of the trial was more common among smokers who received pictorial than those who received text-only warnings (5.7% vs 3.8%; OR, 1.53; 95% CI, 1.02-2.29). Pictorial warnings also increased forgoing a cigarette, intentions to quit smoking, negative emotional reactions, thinking about the harms of smoking, and conversations about quitting.


CONCLUSIONS
Pictorial warnings effectively increased intentions to quit, forgoing cigarettes, quit attempts, and successfully quitting smoking over 4 weeks. Our trial findings suggest that implementing pictorial warnings on cigarette packs in the United States would discourage smoking.


BACKGROUND
clinicaltrials.gov Identifier: NCT02247908.
Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina, Chapel Hill2Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill.
Noel T
NT
Brewer
Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina, Chapel Hill2Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill.
Marissa G
MG
Hall
Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill3School of Media and Journalism, University of North Carolina, Chapel Hill.
Seth M
SM
Noar
Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill.
Humberto
H
Parada
Pacific Institute for Research and Evaluation, Chapel Hill Center, Chapel Hill, North Carolina.
Al
A
Stein-Seroussi
Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina, Chapel Hill.
Laura E
LE
Bach
Pacific Institute for Research and Evaluation, Chapel Hill Center, Chapel Hill, North Carolina.
Sean
S
Hanley
Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina, Chapel Hill2Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill.
Kurt M
KM
Ribisl
D000328:Adult; D004348:Drug Labeling; D005260:Female; D006801:Humans; D033182:Intention; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011356:Product Labeling / Q000379:methods*; D040242:Risk Reduction Behavior; D012907:Smoking / Q000523:psychology; D016540:Smoking Cessation / Q000379:methods / Q000523:psychology; D000074606:Smoking Prevention