Summary of findings 2. Nicotine EC compared to non‐nicotine EC for smoking cessation.
| Nicotine EC compared to non‐nicotine EC for smoking cessation | ||||||
| Patient or population: People who smoke cigarettes Setting: Canada, Italy, New Zealand, UK, USA Intervention: Nicotine EC Comparison: Non‐nicotine EC | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with non‐nicotine EC | Risk with Nicotine EC | |||||
| Smoking cessation at 6 ‐ 12 months Assessed with biochemical validation |
Study population | RR 1.94 (1.21 to 3.13) | 1447 (5 RCTs) | ⊕⊕⊕⊝ MODERATEa,b | ‐ | |
| 7 per 100 | 14 per 100 (9 to 23) | |||||
| Adverse events at 1 week to 6 months Assessed via self‐report |
Study population | RR 1.01 (0.91 to 1.11) | 601 (3 RCTs) | ⊕⊕⊕⊝ MODERATEc | ‐ | |
| 35 per 100 | 35 per 100 (31 to 38) | |||||
| Serious adverse events at 1 week to 1 year Assessed via self‐report and medical records |
Study population | RR 0.95 (0.52 to 1.72) | 1033 (6 RCTs) | ⊕⊕⊝⊝ LOWd | 3 studies reported no events; effect estimate based on the 3 studies in which events were reported | |
| 2 per 100 | 2 per 100 (1 to 3) | |||||
| *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). For cessation, the assumed risk in the control group is based on receipt of moderate‐intensity behavioral stop‐smoking support. The assumed risk for adverse events and serious adverse events is a weighted mean average of quit rates across control groups in contributing studies. CI: Confidence interval; RCT: randomized controlled trial; RR: Risk ratio | ||||||
| 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 | ||||||
aNot downgraded for risk of bias. One of four studies considered high risk of bias; removing this study increased the direction of the effect in favour of the intervention. bDowngraded one level due to imprecision; < 300 events overall. cDowngraded one level due to imprecision: although confidence intervals are narrow, only three studies with 601 participants contribute data. dDowngraded two levels due to imprecision: confidence intervals encompass clinically‐significant harm as well as clinically‐significant benefit.