Prevalence and characteristics of e-cigarette users in Great Britain: Findings from a general population survey of smokers.

"Conflict of interest JB has received an unrestricted research grant from Pfizer. RW undertakes research and consultancy and receives fees for speaking from companies that develop and manufacture smoking cessation medications (Pfizer, J&J, McNeil, GSK, Nabi, Novartis, and Sanofi-Aventis). He also has a share of a patent for a novel nicotine delivery device (not an e-cigarette). There are no other financial relationships with any organisations that might have an interest in the submitted work, particularly electronic cigarette companies."

"JB's post is funded by a fellowship from the UK Society for the Study of Addiction. JB, AM & RW are part of the UK Centre for Tobacco & Alcohol Studies, a UK Clinical Research Collaboration Public Health Research: Centre of Excellence. We are grateful to the International Tobacco Control Policy Evaluation Project for the use of some of their questions on e-cigarettes."