Aveyard 2007.

Methods	Study design: Randomized controlled trial Setting: 26 general practices (primary care clinics), UK Recruitment: 92% volunteers in response to mailings
Participants	925 smokers 51% women, av. age 43, 50% smoked 11 ‐ 20 cpd
Interventions	Therapists: Practice nurses trained to provide cessation support and manage NRT Both interventions included 8 wks of 16 mg nicotine patch 1. Basic support; 1 visit (20 ‐ 40 mins) before quit attempt, phone call on TQD, visits/phone calls at 7 ‐ 14 days and at 21 ‐ 28 days (10 ‐ 20 mins) 2. Weekly support; as 1. plus additional call at 10 days and visits at 14 and 21 days
Outcomes	Abstinence at 12 m (sustained at 1, 4, 12, 26 wks) Validation: CO < 10 ppm at treatment visits, saliva cotinine < 15 ng/ml at follow‐ups
Notes	Not in main analysis; compares higher and lower intensity counselling. Therapists were not full‐time specialist counsellors
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random‐number generator
Allocation concealment (selection bias)	Low risk	Numbered sealed envelopes
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemical validation of abstinence; staff making follow‐up calls were blind
Incomplete outcome data (attrition bias) All outcomes	Low risk	288 (31%) lost to follow‐up, similar across groups, included in ITT analysis