*Williams 2012.

Methods	RCT, USA & Canada. Pts recruited from the community.
Participants	128 smokers (aged 18 to 75) with DSM‐IV TR diagnosis of schizophrenia or schizoaffective disorder. All pts smoked at least 15 CPD and scored at least 7 on the baseline motivation to quit score of the contemplation ladder. Pts did not have any acute exacerbation of psychiatric symptoms, nor psychiatric hospitalisation for the last 6 ms. Their PANSS score was below 70. Female pts consented for birth control if at child bearing age. Pts with the following conditions were excluded: (1) serious suicidal ideation or behaviour; (2) history of drug or alcohol abuse or dependence; (3) clinically significant cardiovascular or cerebrovascular disease in the last 6 ms; (4) any other unstable medical conditions; (5) previous use of varenicline; (6) uncontrolled hypertension; (7) body mass index <15 or >38; (8) use of other smoking cessation aids; (9) use of another investigational drug within 30 days of baseline visit; (10) use of marijuana or other non‐cigarette tobacco products. All pts were interested in quitting smoking. TQD set as 8 days after baseline visit. 98 males; mean age 41.1; 75 white; 38 African American; 6 Asians and 8 other racial group. Average CPD 23. 91 had a diagnosis of schizophrenia. 109 pts were on atypical antipsychotic.
Interventions	1. Varenicline (0.5mg daily for 3 days then twice daily for 4 days then 1mg twice daily) for 12 wks 2. Placebo for 12 wks Both groups received wkly counselling (less than 30 minutes)
Outcomes	Abstinence measured at wk 4, wk 12 and wk 24 (defined as 7‐day point prevalence of abstinence, verified by CO ≤ 10 ppm) Reduction of smoking measured by incidence of achieving 50% or greater reduction from baseline in mean CPD over the past 7 days at wk 12 and 24, as well as change of mean CPD over the previous 7 days at wks 12 and 24. Effects on mental state measured by PANSS, SAS, Columbia Suicide Severity Rating Scale (C‐SSRS) and Cinical Global Impression (CGI).
Source of funding	Sponsored by Pfizer (manufacturer of varenicline)
Primary aim of the study	Smoking cessation
Notes	Varenicline: Placebo in 2:1 ratio.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	The method of sequence generation was not described.
Allocation concealment (selection bias)	Unclear risk	No description of allocation concealment in the reports.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not stated
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not stated
Selective reporting (reporting bias)	Low risk	All expected outcomes
Other bias	Unclear risk	Sponsored by drug company