Ely 2013

Methods	Design: Prospective cohort Recruitment: Letter sent to family practice patients who were current smokers Setting: Single family practice, Colorado USA Inclusion criteria: Want to quit or switch from tobacco cigarettes to ECs Exclusion criteria: None reported
Participants	Letters sent to 640 patients, 48 chose to participate and 44 completed the programme, 4 were lost to follow‐up Of the 44 participants, 66% women, all non‐Hispanic/white, aged 20 ‐ 75 (30% were age 51 ‐ 60), 57% had a high school education or less
Interventions	The 6‐month smoking cessation programme was based on The '5 A's' model and transtheoretical model. Options for treatment were discussed with each participant at the start of the programme. All used an EC, with 16 using bupropion and 2 using varenicline as well Participants were provided with written information on “blu cig” and “smoke tip” ECs, regarding cost, availability, nicotine dosage options
Outcomes	Phone follow‐ups at 2 weeks, 1 month, 3 months, and 6 months At completion of programme (using ITT) Abstinence from smoking and EC use Abstinence from smoking but not EC use ≥ 50% reduction of baseline cigarette consumption (still using ECs)
Notes	No definition of abstinence provided Not clear if 'completed programme' was at 6 months
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	High risk	No blinding
Incomplete outcome data (attrition bias) All outcomes	Low risk	4/48 lost to follow‐up
Selective reporting (reporting bias)	Unclear risk	Unable to determine prespecified outcomes
Other bias	High risk	No definition of abstinence provided Not clear if 'completed programme' was at 6 months.