Tønnesen 1996.

Study characteristics
Methods	Study design: parallel RCT Country: Denmark Recruitment: participants who continued to smoke after participation in 2 previous NRT smoking cessation trials were invited to participate
Participants	89 smokers: previous failed quit attempts; willing to quit completely 30.3% men; average age: 49.5; average cigarettes per day: 22; average FTND: 6.1; salivary cotinine at baseline: 463.5 ng/mL
Interventions	1) Nicotine nasal spray: advice to use ad libitum (up to 10 puffs/hour and 80 puffs/day) 2) Nicotine nasal spray: advice to use 1 puff/hour whilst awake Treatment continued for 6 months following quit day, but tapering could be initiated after 3 months
Outcomes	Continuous smoking abstinence at 12‐month follow‐up (defined as abstinence from week 2 post‐quit day to 12‐month follow‐up); CO‐validated (< 10 ppm) Other abstinence measures: CO‐validated continuous abstinence at 6 months; CO‐validated abstinence allowing for slips (occasionally smoking between 2 visits) at 6 and 12 months Adverse events: measured up to 6 weeks (participants using treatment at this time)
Notes	Pharmacia AB Consumer Pharma, Helsingborg, Sweden, sponsored the study and analysis of saliva for cotinine levels Conflicts of interest: not reported Despite differing dosing instructions between groups, no difference was observed: quote: “Two dosage regimens were used, however, no difference was observed between the fixed and ad libitum dosing group. With a mean daily dose of 16 mg nicotine, most subjects have in fact used the NNS [nicotine nasal spray] once every hour as prescribed.”
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: “This was an open randomized study with active NNS”. No detail on how randomisation achieved
Allocation concealment (selection bias)	Unclear risk	As above
Blinding (performance bias and detection bias) All outcomes	Low risk	Open‐label design – for this comparison, blinding participants was not possible. However, the behavioural support received by the groups was the same and abstinence was biochemically validated, reducing the risk of both performance and detection bias
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Numbers lost to follow‐up not stated (no response to our request to author for figures)