McRobbie 2015.

Study characteristics
Methods	Design: Prospective cohort Recruitment: advertisements in free London newspapers Setting: Smokers' clinic, East London, UK Study start date: February 2013; Study end date: September 2013
Participants	Total N: 40 Inclusion criteria: People who smoke daily who want to quit Aged 18 and older Exclusion criteria: Pregnant and breastfeeding women Current serious medical illness EC use for more than 1 week in the past 45% women, mean age 47 (SD 12), mean cpd 19 (SD 10), mean FTND 5.2 (SD 2.8), 65% in full‐time employment Motivated to quit: Yes E‐cigarette use at baseline: Excluded those who had used EC for more than 1 week in the past
Interventions	EC: Cig‐a‐like Participants attended baseline session 1 week prior to their TQD. On the TQD, participants were provided with an EC (Green Smoke, 1st generation device, 2.4% nicotine cartridges). 2 cartridges a day were supplied initially, with the supply adjusted to actual use later. Attended 4 weekly follow‐up sessions and received standard behavioral support
Outcomes	Cigarette consumption and CO readings collected at each session. Urine sample for cotinine and 3‐HPMA analysis collected at baseline and 4 weeks post‐TQD Change in urinary 3‐HPMA (ng/mg creatinine) at 4 weeks Change in urinary cotinine (ng/mg creatinine) at 4 weeks Change in CO at 4 weeks
Study funding	"This study was funded by a grant given to P. Hajek, H. McRobbie, and M.L.Goniewicz from the UK Medicines and Healthcare Products Regulatory Agency (MHRA). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact."
Author declarations	"H. McRobbie is Clincal Director at The Dragon Institute; reports receiving commercial research grant from Pfizer; and has received speakers bureau honoraria from Johnson&Johnson and Pfizer. M.L. Goniewicz reports receiving commercial research grant from Pfizer. P. Hajek has received speakers bureau honoraria from and is a consultant/advisory board member for the manufacturers of stop‐smoking medications. No potential conflicts of interest were disclosed by the other authors."
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Prospective cohort
Allocation concealment (selection bias)	High risk	Not randomized
Incomplete outcome data (attrition bias) All outcomes	Low risk	7/40 participants were lost to follow‐up
Selective reporting (reporting bias)	Low risk	All predefined outcomes reported