Summary of findings 2. Heated tobacco use compared with abstinence from tobacco.
| Heated tobacco use compared with abstinence from tobacco | ||||||
| Patient or population: people who smoke Setting: USA, Japan, UK, South Korea Intervention: heated tobacco use Comparison: abstinence from tobacco | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | № of participants (studies) | Certainty of the evidence (GRADE) | Comments | |
| Risk with abstinence from tobacco | Risk with heated tobacco use | |||||
| Smoking cessation – not measured | — | — | — | — | — | — |
| Adverse events – measured by self‐report | Study population | RR 1.12 (0.86 to 1.46) | 237 (2 RCTs) | ⊕⊝⊝⊝ Very lowa,b | — | |
| 468 per 1000 | 525 per 1000 (403 to 684) | |||||
| Serious adverse events – measured by self‐report and medical records | Study population | — | 533 (5 RCTs) | ⊕⊝⊝⊝ Very lowc,d | No serious adverse events were reported. | |
| See comment | See comment | |||||
| NNAL at follow‐up – measured in urine | — | — | LMD 0.50 higher (0.34 higher to 0.66 higher) | 382 (5 RCTs) | ⊕⊕⊕⊝ Moderated | LMD has no units as it is calculated from the logarithm of biomarker measurements. |
| COHb at follow‐up – measured in blood | LMD 0.69 higher (0.07 higher to 1.31 higher) for analyses using intention‐to‐treat, but LMD 0.32 lower (1.04 lower to 0.39 higher) for per‐protocol analyses. | 212 (3 RCTs) | ⊕⊝⊝⊝ Very lowa,d,e | Reported narratively due to inconsistency of results across subgroups. | ||
| *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; COHb: carboxyhaemoglobin; LMD: difference in means of log‐transformed measurements; NNAL: 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol; RCT: randomised 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. | ||||||
aDowngraded one level for imprecision: confidence intervals contained clinically meaningful benefit and clinically meaningful harm. bDowngraded two levels for risk of bias: all studies were considered at high risk of bias. cDowngraded two levels for imprecision: no serious adverse events occurred so confidence intervals could not be calculated. dDowngraded one level for risk of bias: two of the five studies were considered high risk of bias, while three had uncertain risk of bias. eDowngraded two levels for inconsistency: there was unexplained heterogeneity and results were inconsistent across subgroups and sensitivity analyses.