Schnoll 2010a.

Study characteristics
Methods	Study design: parallel RCT Country: USA Recruitment: community volunteers
Participants	575 adult smokers of > 10 cigarettes per day for > 1 year, motivated to quit 53% men, average age 48, average cigarettes per day 21.1, average FTND 5.3
Interventions	1) 21 mg/24‐hour patch for 24 weeks 2) 21 mg/24‐hour patch for 8 weeks, followed by 16 weeks of placebo patch
Outcomes	7‐day PPA at 12 months (also reported for 24 weeks) Validation: CO ≤ 10 ppm Adverse events: measured throughout treatment (24 weeks), and also at 52‐week follow‐up
Notes	This study was supported by a Transdisciplinary Tobacco Use Research Center Grant from the National Cancer Institute and the National Institute on Drug Abuse (P50 CA/DA84718 and P50 CA143187). Conflicts of interest: Dr. Lerman has served as a consultant to GlaxoSmithKline, one company that manufactures the nicotine patch. She has also served as a consultant or has received research funding from AstraZeneca, Pfizer, and Novartis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "computer‐based randomization table"
Allocation concealment (selection bias)	Unclear risk	Not specified
Blinding (performance bias and detection bias) All outcomes	Low risk	Quote: "supply of patches was prepackaged and coded with participant information. The computer program linked the randomization to the patch supply, and only the database manager could link identification with treatment allocation."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropouts included as smokers in outcome data. Similar number of dropouts in both groups