Summary of findings 2. Longer compared to shorter duration of combination nicotine replacement therapy for smoking cessation.
| Longer compared to shorter duration of combination nicotine replacement therapy for smoking cessation | ||||||
| Patient or population: people who smoke Setting: any; studies conducted in: USA Intervention: longer duration combination NRT (nicotine patch plus a fast‐acting form of NRT) Comparison: shorter duration combination NRT (nicotine patch plus a fast‐acting form of NRT) | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with shorter duration NRT | Risk with longer duration NRT | |||||
| Smoking cessation ‐ 16 weeks versus 8 weeks | Study population | RR 0.96 (0.75 to 1.23) | 637 (1 RCT) | ⊕⊝⊝⊝ Very lowa,b | ‐ | |
| 285 per 1000 | 274 per 1000 (214 to 351) | |||||
| Smoking cessation ‐ 6 weeks versus 2 weeks | Study population | RR 1.11 (0.94 to 1.31) | 987 (1 RCT) | ⊕⊕⊝⊝ Lowa,c | ‐ | |
| 351 per 1000 | 390 per 1000 (330 to 460) | |||||
| Overall SAEs ‐ 26 weeks versus 8 weeks | Study population | RR 1.63 (0.60 to 4.42) | 544 (1 RCT) | ⊕⊝⊝⊝ Very lowa,d | ‐ | |
| 22 per 1000 | 36 per 1000 (13 to 99) | |||||
| Overall SAEs ‐ 16 weeks versus 8 weeks | Study population | Not estimable | 637 (1 RCT) | ⊕⊝⊝⊝ Very lowa,d | No events in either arm | |
| Not estimable | Not estimable | |||||
| Overall SAEs ‐ 6 weeks versus 2 weeks | Study population | Not estimable | 987 (1 RCT) | ⊕⊝⊝⊝ Very lowa,d | No events in either arm | |
| Not estimable | Not estimable | |||||
| Treatment withdrawals | Study population | n/a | 0 (0 RCTs) |
n/a | None of our included studies reported usable data on this outcome. | |
| n/a | n/a | |||||
| *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; n/a: not applicable; NRT: nicotine replacement therapy; RCT: randomised controlled trial; RR: risk ratio; SAEs: serious adverse events | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: 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 certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
aDowngraded by one level due to risk of bias: we judged the one included study to be at high risk of bias. bDowngraded by two levels for imprecision: fewer than 300 events and confidence intervals encompass clinically significant benefit as well as clinically significant harm. cDowngraded by one level due to imprecision: confidence intervals encompass no clinically significant difference between groups as well as clinically significant benefit. dDowngraded by two levels due to imprecision: fewer than 100 events overall.