McRobbie 2015

Methods	Design: Prospective cohort Recruitment: advertisements in free London newspapers Setting: Smokers' clinic, East London, UK Inclusion criteria: Daily smokers 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
Participants	Total N: 40 45% women, mean age 47 (SD 12), mean cpd 19 (SD 10), mean FTND 5.2 (SD 2.8), 65% in full‐time employment
Interventions	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 per day were supplied initially, with the supply adjusted to actual use later. Attended 4 weekly follow‐up sessions and received standard behavioural 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
Notes	Previously McRobbie 2014, ID updated in this version to reflect 2015 publication
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
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemical validation used
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