About the Authors

Emma Beard

e.beard@ucl.ac.uk

Current address: Cancer Research UK Health Behaviour Research Centre, University College London, London, United Kingdom

Affiliations Research Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom, Department of Epidemiology and Public Health, University College London, London, United Kingdom

Jamie Brown

Affiliations Research Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom, Department of Epidemiology and Public Health, University College London, London, United Kingdom

Robert West

Affiliation Department of Epidemiology and Public Health, University College London, London, United Kingdom

Colin Angus

Affiliation ScHARR, School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom

Alan Brennan

Affiliation ScHARR, School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom

John Holmes

Affiliation ScHARR, School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom

Eileen Kaner

Affiliation Institute of Health & Society, Newcastle University, Newcastle, United Kingdom

Petra Meier

Affiliation ScHARR, School of Health and Related Research, University of Sheffield, Sheffield, United Kingdom

Susan Michie

Affiliation Research Department of Clinical, Educational and Health Psychology, University College London, London, United Kingdom

Competing Interests

EB's and SM's salaries are funded by the NIHR SPHR. EB is also funded by Cancer Research UK (CRUK). JB is funded by CRUK and the Society for the Study of Addiction; RW is funded by CRUK. EB and JB have both received unrestricted research funding from Pfizer, including for the Smoking Toolkit Study (a sister survey of the ATS). RW has received travel funds and hospitality from, and undertaken research and consultancy for, pharmaceutical companies that manufacture and/or research products aimed at helping smokers to stop. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: EB SM JB RW. Analyzed the data: EB. Wrote the paper: EB. All other authors commented on this first draft and contributed to the final draft: CA AB PM EK JH.