Polosa 2014b

Methods	Design: Prospective cohort study Recruitment: Volunteers, leaflets, cessation service kiosk in hospital Setting: Smoking cessation clinic, Italy Inclusion criteria: Healthy smokers 18 – 60 years old, smoking ≥ 15 conventional cpd for at least 10 years, unwilling to quit Exclusion criteria: none stated
Participants	Total N: 50 40% women, mean age 41, mean cpd 25, mean FTND 6.0, no EC use at baseline, not motivated to quit
Interventions	EC: 2nd generation devices (personal vaporisers ‐ PVs): EGO/CE4 model, filled with tobacco aroma e‐Liquid containing 9 mg/ml nicotine; instructed to use the study products ad libitum (up to a maximum of 5 ml/day; i.e. half vial) Behavioural support: Participants were instructed how to charge, fill, activate and use the EC. Key troubleshooting was addressed and phone numbers were supplied for assistance. “No emphasis on encouragement, motivation and reward for the smoking cessation‐related efforts were provided during the study.”
Outcomes	4, 8, 12 and 24w 30‐day PP verified by CO ≤ 10 ppm Adverse events Cpd, exhaled CO, reduction rates, product usage, and opinions of the EC products
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Not controlled
Allocation concealment (selection bias)	High risk	Not controlled
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemically‐verified abstinence, adverse events collected through study diaries
Incomplete outcome data (attrition bias) All outcomes	Low risk	76% followed up, ITT analysis used, no significant differences in baseline characteristics between completers and those lost to follow‐up
Selective reporting (reporting bias)	Low risk	Unable to determine prespecified outcomes