ISRCTN13288677.

Study name	Can electronic cigarettes and nicotine replacement treatment help reduce smoking in smokers who struggle to quit?
Methods	Pilot single‐centre randomized control trial Setting: Queen Mary University of London, UK Recruitment method not specified.
Participants	Target sample size: 200 Inclusion criteria: 18 years or older Able to provide written informed consent History of failed quit attempts using stop‐smoking medications or stop smoking services, or both Willing to use their allocated harm‐reduction strategy for at least 4 weeks Exclusion criteria: Women who are pregnant or breastfeeding Unable to read/write/understand English Currently using EC or any stop‐smoking products Taking part in other interventional research Have a strong preference to use or not to use NRT or EC
Interventions	1) NRT arm: Will be shown and explained the NRT products available and encouraged to choose a product or product combination that suits their needs Will receive a letter of recommendation as per standard practice and collect their chosen products at local pharmacies Product use will be supervised and adjusted (if required) as part of the behavioral support package. As per local standard practice, NRT will be provided for up to 8 weeks 2) EC arm: Will be shown and explained different EC products commonly used and asked to obtain the product of their choice, either using a voucher for up to GBP 35 to purchase EC at a local vape shop, purchase from other suppliers and claim a refund of up to GBP 35 upon providing a valid receipt, or choose from a limited selection at the smoking cessation clinic Will be encouraged to try different products and liquids if the first purchase does not meet their needs, but after the initial purchase, participants will fund further supplies themselves (this is to mimic the provision of starter packs, an approach that is most likely to be used by routine services)
Outcomes	Participants contacted by phone at 1 week, 4 weeks and 24 weeks after the initial screening session Primary outcomes: Cigarette consumption per day, assessed by self‐report in the follow‐up survey created for the purpose of the study at 1, 4 and 24 weeks post‐quit date/preparation date. Those who report ≥ 50% smoking reduction will be validated with a CO reading in the clinic Secondary outcomes: Use of allocated harm‐reduction strategies Strategy ratings Changes in smoking behavior Proportion of people still using allocated strategy at 6 months
Starting date	January 2017
Contact information	Marzena Orzol, m.orzol@qmul.ac.uk Katie Myers‐Smith, katie.smith@qmul.ac.uk
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