Lindson Nicola, Livingstone-Banks Jonathan, Butler Ailsa R, McRobbie Hayden, Bullen Christopher R, Hajek Peter, Wu Angela Difeng, Begh Rachna, Theodoulou Annika, Notley Caitlin, Rigotti Nancy A, Turner Tari, Fanshawe Thomas, Hartmann-Boyce Jamie
Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, UK.
Wolfson Institute of Population Health, Queen Mary University of London, London, UK.
Cochrane Database Syst Rev. 2025 Nov 10;11(11):CD010216. doi: 10.1002/14651858.CD010216.pub10.
Electronic cigarettes (EC) are handheld electronic vaping devices that produce an aerosol by heating a liquid. People who smoke, healthcare providers, and regulators want to know if EC can help people quit smoking, and if they are safe to use for this purpose. This review update was conducted as part of a living systematic review.
To examine the safety, tolerability, and effectiveness of EC for helping people who smoke tobacco achieve long-term smoking abstinence, in comparison to non-nicotine EC, other smoking cessation treatments, and no treatment.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and PsycINFO to 1 March 2025, reference-checked, and contacted study authors.
We included trials randomising people who smoked to an EC or control condition. We also included uncontrolled intervention studies where all participants received an EC intervention. Studies had to measure an eligible outcome.
Critical outcomes were abstinence from smoking after at least six months, adverse events (AEs), and serious adverse events (SAEs). Important outcomes were biomarkers, toxicants/carcinogens, and longer-term EC use.
We used the RoB 1 tool to assess risk of bias for each study and GRADE to assess evidence certainty.
We followed standard Cochrane methods for screening and data extraction. Where appropriate, we pooled data using random-effects models to calculate risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous outcomes. For continuous outcomes, we calculated mean differences with 95% CIs.
We included 104 completed studies (14 new to this update), representing 30,366 participants, of which 61 were randomised controlled trials (RCTs). We rated 11 included studies as being at low risk of bias, 70 at high risk (including all non-randomised studies), and the remainder at unclear risk overall.
Nicotine EC result in increased quit rates compared to nicotine replacement therapy (NRT) (high-certainty evidence) (RR 1.55, 95% CI 1.28 to 1.88; I² = 0%; 9 studies, 2703 participants). In absolute terms, this might translate to an additional three quitters per 100 (95% CI 2 to 5 more). The rate of occurrence of AEs is probably similar between groups (moderate-certainty evidence (limited by imprecision)) (RR 1.00, 95% CI 0.73 to 1.37; I² = 58%; 7 studies, 2241 participants). SAEs were rare, and there is insufficient evidence to determine whether rates differ between groups due to very serious imprecision (RR 1.22, 95% CI 0.73 to 2.03; I² = 30%; 8 studies, 2950 participants; low-certainty evidence). Nicotine EC probably result in increased quit rates compared to non-nicotine EC (moderate-certainty evidence, limited by imprecision) (RR 1.34, 95% CI 1.06 to 1.70; I² = 0%; 7 studies, 1918 participants). In absolute terms, this might lead to an additional two quitters per 100 (95% CI 0 to 4 more). There is probably little to no difference in the rate of AEs between these groups (moderate-certainty evidence) (RR 1.01, 95% CI 0.95 to 1.08; I² = 0%; 5 studies, 840 participants). There is insufficient evidence to determine whether rates of SAEs differ between groups, due to very serious imprecision (RR 0.98, 95% CI 0.55 to 1.73; I² = 0%; 10 studies, 1717 participants; low-certainty evidence). Compared to behavioural support only or no support, quit rates may be higher for participants randomised to nicotine EC (low-certainty evidence due to risk of bias) (RR 1.78, 95% CI 1.42 to 2.25; I² = 13%; 11 studies, 6819 participants). In absolute terms, this represents an additional three quitters per 100 (95% CI 2 to 5 more). There was some evidence that (non-serious) AEs may be more common in people randomised to nicotine EC (RR 1.22, 95% CI 0.96 to 1.55; I² = 66%; 8 studies, 2485 participants; very low-certainty evidence) but the evidence is uncertain and, again, there was insufficient evidence to determine whether rates of SAEs differed between groups (RR 0.93, 95% CI 0.67 to 1.29; I² = 0%; 15 studies, 4716 participants; very low-certainty evidence). Data from non-randomised studies were consistent with RCT data. The most commonly reported AEs were throat/mouth irritation, headache, cough, and nausea, which tended to dissipate with continued EC use. Very few studies reported data on other outcomes or comparisons; hence, evidence for these is limited, with CIs often encompassing both clinically significant harm and benefit.
AUTHORS' CONCLUSIONS: There is high-certainty evidence that nicotine EC increase quit rates compared to NRT, and moderate-certainty evidence that they probably increase quit rates compared to EC without nicotine. Evidence comparing nicotine EC with behavioural support or no support also suggests benefit, but is less certain due to risk of bias inherent in the study designs. CIs were, for the most part, wide for data on AEs, SAEs, and other safety markers, with no evidence of a difference in AEs between nicotine and non-nicotine EC nor between nicotine EC and NRT, but low-certainty evidence for increased AEs compared with behavioural support/no support. Overall incidence of SAEs was low across all study arms. We did not detect evidence of serious harm from nicotine EC, but longer, larger trials are needed to fully evaluate safety. Included studies tested regulated nicotine-containing EC; illicit products and/or products containing other active substances (e.g. tetrahydrocannabinol (THC)) may have different harm profiles. The main limitation of the evidence base remains imprecision for some comparisons and for safety outcomes due to the relatively small number of RCTs contributing, often with low event rates. Further RCTs are underway. To ensure the review continues to provide up-to-date information to decision-makers, this is a living systematic review. We run and screen searches monthly, with the review updated when relevant new evidence becomes available. Please refer to the Cochrane Database of Systematic Reviews for the review's current status.
Cancer Research UK (PICCTR-2024/100012).
Original 2012 protocol available via DOI: 10.1002/14651858.CD010216. Updated 2023 protocol available via DOI 10.17605/OSF.IO/ZWGSK (https://osf.io/ZWGSK/). 2025 updates to protocol available via DOI: 10.17605/OSF.IO/59M4U (https://osf.io/59M4U/) and DOI: 10.17605/OSF.IO/UPGJC (https://osf.io/UPGJC/).
电子烟是一种手持电子雾化设备，通过加热液体产生气溶胶。吸烟者、医疗服务提供者和监管机构都想知道电子烟是否有助于人们戒烟，以及用于此目的是否安全。本次综述更新是作为一项动态系统综述的一部分进行的。
与不含尼古丁的电子烟、其他戒烟治疗方法及不进行治疗相比，研究电子烟帮助吸烟者实现长期戒烟的安全性、耐受性和有效性。
我们检索了截至2025年3月1日的Cochrane对照试验中心注册库（CENTRAL）、MEDLINE、Embase和PsycINFO，并进行了参考文献核对，还联系了研究作者。
我们纳入了将吸烟者随机分为电子烟组或对照组的试验。我们还纳入了所有参与者均接受电子烟干预的非对照干预研究。研究必须测量符合条件的结局。
关键结局指标为至少六个月后的戒烟情况、不良事件（AE）和严重不良事件（SAE）。重要结局指标为生物标志物、有毒物质/致癌物以及电子烟的长期使用情况。
我们使用RoB 1工具评估每项研究的偏倚风险，并使用GRADE评估证据的确定性。
我们遵循Cochrane标准方法进行筛选和数据提取。在适当情况下，我们使用随机效应模型汇总数据，以计算二分结局的风险比（RR）及其95%置信区间（CI）。对于连续结局，我们计算平均差及其95%CI。
我们纳入了104项完成的研究（本次更新新增14项），共30366名参与者，其中61项为随机对照试验（RCT）。我们将11项纳入研究评为低偏倚风险，70项为高偏倚风险（包括所有非随机研究），其余研究的总体偏倚风险尚不清楚。
与尼古丁替代疗法（NRT）相比，含尼古丁的电子烟可提高戒烟率（高确定性证据）（RR 1.55，95%CI 1.28至1.88；I² = 0%；9项研究，2703名参与者）。从绝对值来看，这可能意味着每100人中会额外增加3名戒烟者（95%CI多2至5名）。两组间AE的发生率可能相似（中度确定性证据（受不精确性限制））（RR 1.00，95%CI 0.73至1.37；I² = 58%；7项研究，2241名参与者）。SAE很少见，由于非常严重的不精确性，没有足够的证据来确定两组间的发生率是否存在差异（RR 1.22，95%CI 0.73至2.03；I² = 30%；8项研究，2950名参与者；低确定性证据）。与不含尼古丁的电子烟相比，含尼古丁的电子烟可能会提高戒烟率（中度确定性证据，受不精确性限制）（RR 1.34，95%CI 1.06至1.70；I² = 0%；7项研究，1918名参与者）。从绝对值来看，这可能会导致每100人中额外增加2名戒烟者（95%CI多0至4名）。两组间AE的发生率可能几乎没有差异（中度确定性证据）（RR 1.01，95%CI 0.95至1.08；I² = 0%；5项研究，840名参与者）。由于非常严重的不精确性，没有足够的证据来确定两组间SAE的发生率是否存在差异（RR 0.98，95%CI 0.55至1.73；I² = 0%；10项研究，1717名参与者；低确定性证据）。与仅接受行为支持或不接受支持相比，随机分配到含尼古丁电子烟组的参与者戒烟率可能更高（由于偏倚风险，为低确定性证据）（RR 1.78，95%CI 1.42至2.25；I² = 13%；11项研究，6819名参与者）。从绝对值来看，这意味着每100人中会额外增加3名戒烟者（95%CI多2至5名）。有一些证据表明，随机分配到含尼古丁电子烟组的人（非严重）AE可能更常见（RR 1.22，95%CI 0.96至1.55；I² = 66%；8项研究，2485名参与者；极低确定性证据），但证据不确定，同样，也没有足够的证据来确定两组间SAE的发生率是否存在差异（RR 0.93，95%CI 0.67至1.29；I² = 0%；15项研究，4716名参与者；极低确定性证据）。非随机研究的数据与RCT数据一致。最常报告的AE是咽喉/口腔刺激、头痛、咳嗽和恶心，这些症状往往会随着电子烟的持续使用而减轻。很少有研究报告其他结局或比较的数据；因此，关于这些方面的证据有限，CI通常既包含临床上有意义的危害，也包含益处。
有高确定性证据表明，与NRT相比，含尼古丁的电子烟可提高戒烟率；有中度确定性证据表明，与不含尼古丁的电子烟相比，含尼古丁的电子烟可能会提高戒烟率。将含尼古丁的电子烟与行为支持或不提供支持进行比较的证据也表明有益，但由于研究设计中固有的偏倚风险，证据不太确定。对于AE、SAE和其他安全指标的数据，CI在很大程度上较宽，没有证据表明含尼古丁和不含尼古丁的电子烟之间或含尼古丁的电子烟与NRT之间的AE存在差异，但与行为支持/不提供支持相比，AE增加的证据为低确定性证据。所有研究组中SAE的总体发生率都很低。我们没有发现含尼古丁的电子烟会造成严重危害的证据，但需要进行更长时间、更大规模的试验来全面评估安全性。纳入研究测试的是受监管的含尼古丁电子烟；非法产品和/或含有其他活性物质（如四氢大麻酚（THC））的产品可能具有不同的危害特征。证据基础的主要局限性仍然是，由于贡献的RCT数量相对较少，且事件发生率通常较低，一些比较和安全结局存在不精确性。更多的RCT正在进行中。为确保本综述继续为决策者提供最新信息，这是一项动态系统综述。我们每月进行检索和筛选，当有相关新证据时，对综述进行更新。有关本综述的当前状态，请参考Cochrane系统评价数据库。
英国癌症研究中心（PICCTR - 2024/100012）。
2012年原始方案可通过DOI：10.1002/14651858.CD010216获取。2023年更新方案可通过DOI 10.17605/OSF.IO/ZWGSK（https://osf.io/ZWGSK/）获取。2025年方案更新可通过DOI：10.17605/OSF.IO/59M4U（https://osf.io/59M4U/）和DOI：10.17605/OSF.IO/UPGJC（https://osf.io/UPGJC/）获取。
