Fast‐acting nicotine replacement therapy showed no clear difference in smoking cessation compared with nicotine patch (high certainty).
It is very uncertain whether fast‐acting nicotine replacement therapy changes treatment withdrawals compared with nicotine patch (very low certainty).
Preloading nicotine replacement therapy (NRT) probably leads to higher smoking cessation compared with standard‐use NRT (moderate certainty).
Preloading nicotine replacement therapy (NRT) showed no clear difference in overall serious adverse events compared with standard‐use NRT (low certainty).
It is very uncertain whether preloading nicotine replacement therapy (NRT) changes treatment withdrawals compared with standard‐use NRT (very low certainty).
Nicotine replacement therapy may leads to higher biochemically validated smoking cessation at the latest point in… compared with control (low certainty).
Nicotine replacement therapy showed no clear difference in mean birthweight (g) compared with control (low certainty).
Nicotine replacement therapy showed no clear difference in miscarriage and spontaneous abortion compared with control (low certainty).
Bupropion plus nicotine replacement therapy (NRT) showed no clear difference in smoking cessation (at least six months of compared with NRT alone (low certainty).
Bupropion plus nicotine replacement therapy (NRT) showed no clear difference in serious adverse events compared with NRT alone (low certainty).
Bupropion plus nicotine replacement therapy (NRT) showed no clear difference in dropouts due to treatment compared with NRT alone (low certainty).
Nicotine replacement therapy for smoking cessation showed no clear difference in mean weight change (kg) at end of treatment compared with placebo (moderate certainty).
The intervention showed no clear difference in number of smokers receiving nicotine gum/replacement therapy… (low certainty).
Combination leads to higher smoking cessation compared with single‐form nicotine replacement therapy (high certainty).
Combination showed no clear difference in overall serious adverse events compared with single‐form nicotine replacement therapy (low certainty).
It is very uncertain whether combination changes treatment withdrawals compared with single‐form nicotine replacement therapy (very low certainty).
It is very uncertain whether longer changes smoking cessation ‐ 16 weeks versus 8 weeks compared with shorter duration of combination nicotine replacement therapy (very low certainty).
Longer showed no clear difference in smoking cessation ‐ 6 weeks versus 2 weeks compared with shorter duration of combination nicotine replacement therapy (low certainty).
It is very uncertain whether longer changes overall SAEs ‐ 26 weeks versus 8 weeks compared with shorter duration of combination nicotine replacement therapy (very low certainty).