Humair 2014.

Study characteristics
Methods	Design: Prospective cohort Recruitment: People attending an outpatient clinic Setting: University hospital outpatient clinic, Switzerland Study start date/end date: Not specified
Participants	Total N: 17 Inclusion criteria: Wish to reduce tobacco use or had failed to stop smoking using varenicline, bupropion or NRT in past Inclusion based on specific population characteristic: No Mean 23 cpd, 82% had a psychiatric illness Motivated to quit: Yes E‐cigarette use at baseline: Not specified
Interventions	EC: Cig‐a‐like Offered an EC with nicotine 59% also reported using NRT or varenicline in addition to EC
Outcomes	Smoking cessation and reduction by at least 30% at 12 months (self‐report) Adverse events No significant side effects
Study funding	Not specified
Author declarations	Not specified
Notes	Abstract only, hence little detail available Not clear if EC was provided by clinic or if participants had to buy their own
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	Unclear risk	Numbers lost to follow‐up not reported
Selective reporting (reporting bias)	Unclear risk	Unable to determine prespecified outcomes