Comparison 4.

Varenicline (1.0 mg 2/d) vs placebo

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Continuous or sustained abstinence at longest follow‐up (24+ weeks)	27	12625	Risk Ratio (M‐H, Fixed, 95% CI)	2.24 [2.06, 2.43]
2 Abstinence at six months	25	12304	Risk Ratio (M‐H, Fixed, 95% CI)	2.25 [2.08, 2.44]
3 Abstinence for long‐term use (up to 52 weeks) of varenicline	4	2170	Risk Ratio (M‐H, Fixed, 95% CI)	3.64 [2.81, 4.72]