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Cigarette pack messages about toxic chemicals: a randomised clinical trial
  1. Noel T Brewer1,2,
  2. Michelle Jeong1,2,
  3. Jennifer R Mendel1,
  4. Marissa G Hall1,2,
  5. Dongyu Zhang3,
  6. Humberto Parada Jr4,
  7. Marcella H Boynton1,2,
  8. Seth M Noar2,5,
  9. Sabeeh A Baig1,
  10. Jennifer C Morgan,
  11. Kurt M Ribisl1,2
  1. 1 Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
  2. 2 Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina, USA
  3. 3 Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
  4. 4 Division of Epidemiology and Biostatistics, Graduate School of Public Health, San Diego State University, San Diego, California, USA
  5. 5 School of Media and Journalism, University of North Carolina, Chapel Hill, North Carolina, USA
  1. Correspondence to Dr Noel T Brewer, Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina, Chapel Hill NC 27599, USA; ntb{at}


Background The USA can require tobacco companies to disclose information about harmful and potentially harmful chemicals in cigarette smoke, but the impact of these messages is uncertain. We sought to assess the effect of placing messages about toxic chemicals on smokers’ cigarette packs.

Methods Participants were 719 adult cigarette smokers from California, USA, recruited from September 2016 through March 2017. We randomly assigned smokers to receive either factual messages about chemicals in cigarette smoke and their health harms (intervention) or messages about not littering cigarette butts (control) on the side of their cigarette packs for 3 weeks. The primary trial outcome was intention to quit smoking.

Results In intent-to-treat analyses, smokers whose packs had chemical messages did not have higher intentions to quit smoking at the end of the trial than those whose packs had control messages (P=0.56). Compared with control messages, chemical messages led to higher awareness of the chemicals (28% vs 15%, P<0.001) and health harms (60% vs 52%, P=0.02) featured in the messages. In addition, chemical messages led to greater negative affect, thinking about the chemicals in cigarettes and the harms of smoking, conversations about the messages and forgoing a cigarette (all P<0.05).

Discussion Chemical messages on cigarette packs did not lead to higher intentions to quit among smokers in our trial. However, chemical messages informed smokers of chemicals in cigarettes and harms of smoking, which directly supports their implementation and would be critical to defending the messages against cigarette company legal challenges.

Trial registration number NCT02785484.

  • prevention
  • public policy
  • packaging and labelling
  • carcinogens
  • smoking caused disease

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  • Contributors NTB had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: NTB, MHB, JRM, MGH, SMN, SAB, JCM and KMR. Acquisition, analysis or interpretation of data: NTB, MJ, DZ, HP and MHB. Drafting of the manuscript: NTB, MJ, JRM and MGH. Critical revision of the manuscript for important intellectual content: all authors. Statistical analysis: NTB, MJ, DZ and MHB. Obtained funding: NTB, MGH, SMN and KMR. Administrative, technical or material support: NTB, MJ, JRM, MGH, HP, SAB, JCM and KMR. Study supervision: NTB and JRM.

  • Funding Research reported in this publication was supported by grant number P50CA180907 from the National Cancer Institute and FDA Center for Tobacco Products (CTP). T32CA057726 from the National Cancer Institute of the National Institutes of Health supported MGH’s time writing the paper.

  • Disclaimer The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH or the Food and Drug Administration. The funding institutions had no role in the design and conduct of the study; collection, management, analysis and interpretation of the data; preparation, review or approval of the manuscript; and decision to submit the manuscript for publication.

  • Competing interests None of the authors have received funding from tobacco product manufacturers. NTB and KMR have served as paid expert consultants in litigation against tobacco companies. The other authors declare no conflicts of interest.

  • Patient consent Obtained.

  • Ethics approval The University of North Carolina institutional review board approved the trial procedures.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement Due to our university’s requirements on grant-funded research, we can share the study data with a signed data use agreement. Investigators wishing to access the data may contact the first or last author of the paper.

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