Treatment effects and adverse events
Varenicline
Three RCTs[31, 35, 37] involving 195 smokers reported the smoking cessation effects of Varenicline. The results of the subgroup analysis showed that in less than 12 weeks, Varenicline improved the smoking cessation rate of tobacco dependents compared with the placebo group (OR = 1.22, 95% CI: [3.44, 57.07], p <0.001). However, when the treatment duration was longer than 12 weeks, the difference between the two groups was not statistically significant (OR = 2.32, 95% CI: [0.62, 8.70], = 0.21). The overall effect size indicated that the intervention was effective (OR = 6.27, 95% CI: [2.49, 15.78], p < 0.001; very low certainty; Figure 3).