Ockene 1992.

Methods	Study design: Randomized controlled trial Setting: Cardiac catheterization labs at 3 hospitals, USA Recruitment: inpatient smokers or recent quitters with coronary artery stenosis, following arteriography
Participants	267 smokers (256 surviving at 12 m follow‐up) av. age 53, av. cpd 25
Interventions	Therapists: Masters‐level health educators 1. Minimal intervention ‐ 10‐min advice and review of an information sheet 2. Inpatient counselling session, 30 mins, outpatient visits and telephone calls. Opportunity to attend group programme
Outcomes	Abstinence at 12 m (sustained for 6 m) Validation: saliva cotinine < 20 ng/ml
Notes	Average length of contact for intervention was 1.22 hrs (20 mins to > 5 hrs)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not stated
Allocation concealment (selection bias)	Unclear risk	No details given
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemical validation of abstinence
Incomplete outcome data (attrition bias) All outcomes	Low risk	No mention of losses to follow‐up and all survivors included in denominators.