Summary of findings 2. Active NRT compared with placebo ‐ rs16969968 ‐ non‐Hispanic white for smoking cessation.

Active NRT compared with placebo ‐ rs16969968 ‐ non‐Hispanic white for smoking cessation
Patient or population: people who smoke Setting: community and healthcare settings Intervention: active NRT Comparison: placebo
Outcomes	Anticipated absolute effects* (95% CI)		Relative effect (95% CI)	No. of participants (studies)	Quality of the evidence (GRADE)	Comments
	Risk with placebo ‐ rs16969968 ‐ non‐Hispanic white	Risk with active NRT
End of treatment	Study population		RR 1.38 (0.97 to 1.98)	1127 (2 RCTs)	⊕⊕⊕⊝ MODERATEa,b	Pooled result across studies, including all genotypes. Between‐genotype group heterogeneity P value = 0.03 (see results for individual subgroups in below rows)
	251 per 1000	346 per 1000 (243 to 496)
End of treatment ‐ homozygous major	Study population		RR 1.01 (0.77 to 1.33)	449 (2 RCTs)	⊕⊕⊝⊝ LOWa,c	For participants with homozygous major genotype, low‐quality evidence suggests no effect.
	333 per 1000	337 per 1000 (257 to 443)
End of treatment ‐ heterozygous	Study population		RR 1.85 (1.33 to 2.59)	550 (2 RCTs)	⊕⊕⊕⊕ HIGH	For participants with heterozygous genotype, high‐quality evidence shows effect in favour of intervention.
	193 per 1000	358 per 1000 (257 to 501)
End of treatment ‐ homozygous minor	Study population		RR 1.80 (0.45 to 7.23)	128 (2 RCTs)	⊕⊕⊝⊝ LOWd	For participants with homozygous minor genotype, low‐quality evidence shows that point estimate favours intervention, but 95% CI crosses null effect.
	233 per 1000	420 per 1000 (105 to 1000)
*The risk in the intervention group (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; NRT: nicotine replacement therapy; RCT, randomised controlled trial; RR: risk ratio.
GRADE Working Group grades of evidence. High quality: We are very confident that the true effect lies close to that of the estimate of the effect. Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of the effect. Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the estimate of effect.

^aDowngraded one level owing to imprecision: Optimal information size criterion is met, but 95% CIs include the null effect and fail to exclude important benefit or important harm.

^bNot downgraded owing to inconsistency, as large statistical heterogeneity can be explained by differences in genotypes.

^cDowngraded one level owing to inconsistency: unexplained heterogeneity.

^dDowngraded two levels owing to serious imprecision: optimal information size criterion not met, and 95% CIs include the null effect and fail to exclude important benefit or important harm.