Funding for this research was provided by:
Cancer Research UK (C1417/A22962)
School for Public Health Research
Society for the Study of Addiction
UK Centre for Tobacco and Alcohol Studies
Received: 10 February 2020
Accepted: 6 December 2020
First Online: 6 January 2021
Ethics approval and consent to participate
: Ethical approval from University College London’s Research Ethics Committee (CEHP/2016/556) and participants provided online written consent to having their anonymous data used for scientific research purposes.
: Not applicable.
: CG, OP and SM have no competing interests to declare. JB and EB have received unrestricted research grants from Pfizer related to smoking cessation. RW has received research funding and undertaken consultancy for companies that manufacture smoking cessation medications.