Wong 2012

Methods	Country: Canada Setting: 2 Toronto hospitals Aim: "to determine the effectiveness and safety of a perioperative smoking cessation intervention including varenicline and counseling versus placebo and counseling to increase short‐ and long‐term abstinence in surgical patients" Study Design: Randomised placebo‐controlled double‐blind trial Dates conducted: June 2008 ‐ November 2010 Analysis: Sample sizes of 145 in each group, estimated to give 80% power to detect a risk difference of 15% at 12 months between active and placebo groups
Participants	286 non‐cardiac elective surgery patients, smoking 10+ CPD, no abstinence > 3m in last year, scheduled for surgery in the next 8 ‐ 30 days. Allocated to varenicline (151) or placebo (135). Mean age 52.6, 47% women, mean CPD 17.4, mean FTND 4.8
Interventions	All participants received 2 standardised 15‐min counselling sessions by researchers, 1 in pre‐op clinic and 1 24 hours after surgery, supplemented by written materials. All participants retained the same counsellor throughout the process Weekly counselling phone calls for 4 weeks, and at the end of 8 weeks. From 3 ‐ 12 months, phone calls every 4 weeks for smoking status, nicotine dependence, stage of change, CPD, brief (< 5 mins) counselling. TQD was set for 24 hours before surgery, and medication begun 7 days before TQD 1. Varenicline: 12 wks standard regimen, 1st wk titrated 2. Placebo: Identical‐looking tablets and regimen Participants were invited to visit the hospital at 3, 6, and 12m, for assessment and testing. Participants unable to visit the hospital were sent a self‐test urinary kit
Outcomes	7‐day PPA at 12m; abstinence on TQD; 7‐day PPA at 3m and 6m. Self‐reported changes in CPD and stage of change at 3, 6 and 12m Validation: Expired CO and urinary cotinine (cut‐offs not given)
Treatment type	Medication: VARENICLINE
Notes	Supported by Canadian academic institutes and Pfizer Canada New for 2016 update
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Smokers were randomly assigned to receive varenicline (Pfizer Inc., Kirkland, Quebec, Canada) or matching placebo using a computer‐generated randomization list at each center. A stratified randomization with blocks of 40, based on the smoker’s stage of change, was employed because the stage of change may predict successful abstinence from smoking."
Allocation concealment (selection bias)	Low risk	"The patient assignments were placed into sequentially numbered, opaque sealed envelopes, and were kept by an independent research pharmacist at each center who was not involved with patient care or outcome assessments. For each patient, the research pharmacist opened the envelope and provided the research coordinator with the medication or placebo (lactose, identical in appearance) according to the randomization schedule."
Blinding (performance bias and detection bias) All outcomes	Low risk	"The patients, healthcare personnel, and research staff were blinded to the randomization throughout the study period."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Losses fully reported: Varenicline: 6 discontinued treatment, 11 discontinued follow‐up. Placebo: 6 discontinued treatment, 10 discontinued follow‐up. ITT analyses conducted
Selective reporting (reporting bias)	Low risk	None noted
Other bias	Low risk	None noted