Wang 2009
| Methods | Country: China (10 sites), Singapore (3 sites), Thailand (2 sites) Aim: To test the efficacy and safety of varenicline for smoking cessation in Chinese, Singaporean and Thai smokers Dates conducted: Not stated Study Design: Double‐blind placebo‐controlled RCT. Analysis: Power calculation (≥ 90%, alpha = 0.05); ITT denominators and logistic regression model including treatment with site, country, FTND score, CPD and time to first cigarette. No interactions found |
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| Participants | 333 healthy adult volunteers, aged 18 ‐ 75; allocated to varenicline (165), or placebo (168). 97% men, mean age 39, BMI > 15 and < 38 or weight > 45.5 kg, mean CPD 20, mean FTND score 5.4. Treatment groups were comparable at baseline. 58% had never tried to quit before Exclusion criteria: Standard pharmacotherapy trial criteria, plus any use of NRT or bupropion in previous 6m | |
| Interventions | 1. Varenicline 1.0 mg x 2/day 2. Placebo tablet x 2/day Treatment period 12 wks, 1st wk titrated dosage. All participants received a smoking cessation booklet at baseline, + brief counselling (≤ 10 mins) at each clinic visit, except for wks 5 and 7, when counselling was conducted by phone In follow‐up phase, clinic visits at wks 13, 16, 20, 24 plus brief phone calls at wks 14, 18, 22. Dosing and CO checked at each visit, and lab samples taken at wks 12 and 24 | |
| Outcomes | Primary outcome: CO‐confirmed CAR for wks 9 ‐ 12 Secondary outcomes: CO‐confirmed CAR for wks 9 ‐ 24; 7‐day PPA at 24 wks Validation by expired CO < 10 ppm Other outcomes: adverse events; long‐term quit rates Dropouts and losses to follow‐up were included in the analyses as continuing smokers (ITT analysis) Attrition in treatment phase was 3.0% in varenicline group, and 3.6% in placebo group. By wk 24, 4.2% of had dropped out of each group | |
| Treatment type | Medication: VARENICLINE | |
| Notes | The trial was funded by Pfizer Inc New for 2010 update | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | "eligible subjects were randomized in a 1:1 ratio" |
| Allocation concealment (selection bias) | Unclear risk | See above |
| Blinding (performance bias and detection bias) All outcomes | Unclear risk | "double‐blind", but no further information |
| Incomplete outcome data (attrition bias) All outcomes | Unclear risk | No information, but very high compliance rates |
| Selective reporting (reporting bias) | Low risk | All expected and predicted outcomes covered |
| Other bias | Unclear risk | None noted |