Hall 2011.

Methods	BUPROPION Randomized controlled trial Setting: Clinic, USA Recruitment: community volunteers
Participants	406 smokers of ≥ 10 cpd 39% F, av age 41, av cpd 19, mean FTND 4.9
Interventions	Relapse prevention study. All arms received same cessation intervention (5 sessions group counselling, 10wks NRT and 12wks bupropion at 150 mg/d for first 3 days and 300 mg/d for remainder). After cessation treatment ended: 1. Bupropion for 40wks (300mg/d) 2. As per 1, but placebo 3. As per 1, plus 11 sessions of individual CBT over 40 wks 4. As per 3, but placebo 5. No further treatment
Outcomes	7d PP at 2y CO ≤ 10 ppm and urinary cotinine ≤ 60 ng/ml
Notes	New for 2013 update. Study report does not present absolute values for N abstinent, only adjusted ORs. N quit extrapolated from graph. Group 5 does not contribute to any analyses. Funding: National Institute on Drug Abuse
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	“Randomly assigned,” methods not specified
Allocation concealment (selection bias)	Unclear risk	Not specified
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Participants blinded successfully but blinding of staff not reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	83% followed up at 2y, similar rates across groups