Bolliger 2007.

Study characteristics
Methods	Study design: parallel RCT Country: South Africa Recruitment: by a newspaper advertisement
Participants	100 smokers: aged ≥ 18 years, > 15 cigarettes per day, smoked for > 3 years, exhaled CO > 10 ppm, serious quit attempts in the past 12 months, willing to stop smoking immediately 60% men; average age: 43.1 years; average cigarettes per day: 23.4; average FTND: 5.6; average exhaled CO: 25.5 ppm
Interventions	1) Nicotine mouth spray 2) Nicotine gum 3) Nicotine inhaler Participants in all groups were advised to use their allocated product for 12 weeks from quit day, ad libitum (recommended 6 to 12 actuations/cartridges a day)
Outcomes	Continuous smoking abstinence at 6‐month follow‐up (not a puff since quit day); CO‐validated (< 10 ppm) Other abstinence measures: self‐reported continuous at 12‐month follow‐up; self‐reported PPA at 12‐month follow‐up; CO‐validated PPA at 6 months Adverse events: measured at each visit to final follow‐up at 1 year (treatment only lasted 12 weeks)
Notes	The trial was fully funded by NicoNovum AB (the pharmaceutical company who manufactured the mouth spray tested) Conflicts of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient details given to make a judgement Quote: “Subjects were then randomly allocated (block randomization of 4, i.e. after each block of 4 subjects, 2 were allocated to the spray, 1 to the gum and 1 to the inhaler) to the mouth spray (n = 50), the gum (n = 25) and the inhaler (n = 25) group, irrespective of their preference.”
Allocation concealment (selection bias)	Unclear risk	As above
Blinding (performance bias and detection bias) All outcomes	High risk	Open‐label trial. No description is given of any attempts to blind participants or assessors. 7 participants changed their product during treatment: 2 from spray to gum and inhaler (1 each), 2 from gum to spray and inhaler (1 each), 3 from inhaler to spray (n = 2) and gum (n = 1); all 7 were considered treatment failures according to the principle of intention‐to‐treat
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Only 46% of participants attended final follow‐up (12 months), i.e. less than 50% of those randomised. There was differential dropout between groups (60% spray; 40% gum; 56% inhaler), with a 20% difference between the spray and gum groups.