Lifrak 1997

Methods	Setting: substance abuse outpatient facility, USA Recruitment: community volunteers
Participants	69 smokers (≥ 1 pack/day); 62% female, average age 39, average cigs/day 25
Interventions	All received nicotine patch (24 hours, 10 weeks tapered dose) 1. Moderate intensity: 4 meetings with nurse practitioner who reviewed self‐help materials and instructed in patch use 2. High intensity: as 1 plus 16 weekly 45‐minute cognitive‐behavioural relapse prevention therapy from clinical social worker or psychiatrist
Outcomes	Abstinence at 12 months (1‐week point prevalence) Validation: urine cotinine for some participants, but no corrections made for misreporting
Notes	High‐intensity participants attended median of 8¼ sessions
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation method not described
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	No information provided
Blinding of outcome assessment (detection bias) All outcomes	High risk	Incomplete urinary cotinine samples collected, so not used to validate abstinence. Intervention group received significantly more intensive face‐to‐face contact, differential misreport possible
Incomplete outcome data (attrition bias) All outcomes	Low risk	12 administrative dropouts/exclusions not included, treatment group not specified