Croghan 2003.

Study characteristics
Methods	Study design: parallel RCT Country: USA Recruitment: multicentre community volunteers
Participants	1384 smokers (≥ 15 cigarettes per day) 42% men, average age 42, average cigarettes per day: 26
Interventions	1) 15 mg/16‐hour nicotine patch plus 0.5 mg/dose nasal spray, maximum 5/hour, 40/day, for 6 weeks 2) Nicotine nasal spray only 3) Nicotine patch only
Outcomes	PPA at 6 months Validation: CO Adverse events: measured to 6 months (treatment duration was 6 weeks)
Notes	This study was supported in part by Public Health Service Grants CA‐25224, CA‐37404, CA63849, CA‐35269, CA‐52352, CA‐37417, CA‐63848, CA‐35195, and CA‐35103 from the National Cancer Institute, Department of Health and Human Services. Medication was provided by McNeil Consumer Products Conflicts of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation by Mayo Clinic Co‐ordinating Centre
Allocation concealment (selection bias)	Low risk	Quote: "Treatment assignment was carried out using a dynamic allocation procedure" which took account of stratification by gender, cigarettes per day, years smoking, study site
Blinding (performance bias and detection bias) All outcomes	High risk	Open‐label study
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropouts reported in detail. 34% of participants completed study. Losses to follow‐up similar across groups, treated as non‐abstinent