Cummings 2011.

Study characteristics
Methods	Study design: parallel RCT Country: USA Recruitment: from callers to the New York State Smokers’ Quit Line (NYSSQL) between July and October of 2008
Participants	2806 smokers: aged ≥ 18 years, ≥ 10 cigarettes per day, interested in using nicotine patch to help them stop smoking, no known contraindications to the patch, willing to make quit attempt within 2 weeks 44.3% men; average age: 45 to 54 years (mode); average cigarettes per day: 20 to 29 (mode); time to first cigarette: within 5 minutes (mode category)
Interventions	1) 2 weeks of free nicotine patch treatment provided 2) 4 weeks of free nicotine patch treatment provided 3) 6 weeks of free nicotine patch treatment provided All participants received the quit‐line’s standard cessation guide, providing tips on quitting smoking, along with information on the benefits of smoking cessation. In addition, all participants received 1 x 10‐ to 15‐minute proactive follow‐up call conducted 2 weeks after initially contacting the quit‐line. The counselling call was intended to help participants address barriers to quitting and prompt them to use the medications sent to them.
Outcomes	Self‐reported 30‐day PPA at 7‐month follow‐up Other abstinence measures: self‐reported 7‐day PPA at 7 months No biochemical validation Adverse events: not measured
Notes	Funded by the New York State Department of Health Conflicts of interest: not reported The mean number of patches used was significantly greater in the groups that received more medication (2‐week group: 13.0; 4‐week group: 16.3; 6‐week group: 20.1)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information given Quote: “Eligible participants were assigned according to a prerandomized assignment sheet”
Allocation concealment (selection bias)	Unclear risk	Insufficient information given Quote: “Eligible participants were assigned according to a prerandomized assignment sheet”
Blinding (performance bias and detection bias) All outcomes	High risk	Quote: “Quit line phone coaches were not aware of the callers’ group assignment.” However, participants were not blinded and it is unclear whether abstinence assessors were blind to allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	59.9% of participants responded to the follow‐up survey overall, with a similar response rate between groups – 58% in 2‐week group; 62% in the 4‐week group; 60% in the 6‐week group