Abstract
Background: Some pregnant smokers try e-cigarettes, but effectiveness and safety of such use are unknown. Objectives: To compare effectiveness and safety of nicotine patches and e-cigarettes in pregnancy. Design: A pragmatic multi-centre randomised controlled trial. Setting: Twenty-three hospitals across England, and a Stop Smoking Service in Scotland. Participants: One thousand one hundred and forty pregnant daily smokers (12–24 weeks’ gestation) motivated to stop smoking, with no strong preference for using nicotine patches or e-cigarettes. Interventions: Participants in the e-cigarette arm were posted a refillable e-cigarette device with two 10 ml bottles of tobacco-flavoured e-liquid (18 mg nicotine). Participants in the nicotine patches arm were posted a 2-week supply of 15 mg/16-hour nicotine patches. Supplies were provided for up to 8 weeks. Participants sourced further supplies themselves as needed. Participants in both arms received support calls prior to their target quit date, on the quit date, and weekly for the next 4 weeks. Outcome measures: The primary outcome was validated prolonged abstinence at the end of pregnancy. Participants lost to follow-up or not providing biochemical validation were included as non-abstainers. Secondary outcomes included self-reported abstinence at different time points, treatment adherence and safety outcomes. Results: Only 55% of self-reported abstainers mailed back useable saliva samples. Due to this, validated sustained abstinence rates were low (6.8% vs. 4.4% in the e-cigarettes and nicotine patches arms, respectively, risk ratio = 1.55, 95% confidence interval 0.95 to 2.53; Bayes factor = 2.7). In a prespecified sensitivity analysis that excluded abstainers using non-allocated products, the difference became significant (6.8% vs. 3.6%, risk ratio = 1.93, 95% confidence interval 1.14 to 3.26; Bayes factor = 10). Almost a third of the sample did not set a target quit date and the uptake of support calls was low, as was the initial product use. At end of pregnancy, 33.8% versus 5.6% of participants were using their allocated product in the e-cigarettes versus nicotine patches arm (risk ratio = 6.01, 95% confidence interval 4.21 to 8.58). Regular use of e-cigarettes in the nicotine patches arm was more common than use of nicotine replacement products in the e-cigarette arm (17.8% vs. 2.8%). Rates of adverse events and adverse birth outcomes were similar in the two study arms, apart from participants in the e-cigarette arm having fewer infants with low birthweight (<2500 g) (9.6% vs. 14.8%, risk ratio = 0.65, 95% confidence interval 0.47 to 0.90; Bayes factor = 10.3). Limitations: Low rates of validation reduced the study power. A substantial proportion of participants did not use the support on offer sufficiently to test its benefits. Sample size may have been too small to detect differences in less frequent adverse effects. Conclusions: E-cigarettes were not significantly more effective than nicotine patches in the primary analysis, but when e-cigarettes use in the nicotine patches arm was accounted for, e-cigarettes were almost twice as effective as patches in all abstinence outcomes. In pregnant smokers seeking help, compared to nicotine patches, e-cigarettes are probably more effective, do not pose more risks to birth outcomes assessed in this study and may reduce the incidence of low birthweight.
Original language | English |
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Pages (from-to) | 1-53 |
Number of pages | 53 |
Journal | Health Technology Assessment |
Volume | 27 |
Issue number | 13 |
DOIs | |
Publication status | Published - Jul 2023 |
Bibliographical note
Funding Information:The study was sponsored by the QMUL Joint Management Research Office. Ethical approval was obtained from the National Research Ethics Service Committee London –South East (ref: 17/ LO/0962) on 29 June 2017 and approvals were obtained from the Health Research Authority on 24 July 2017.
Funding Information:
Primary conflicts of interest: Linda Bauld is on the Public Health Research (PHR) Research Funding Board. Peter Hajek received research funding from and provided consultancy to Pfizer Inc. (New York, NY, USA). Hayden McRobbie received honoraria for speaking at smoking cessation meetings and attending advisory board meetings that have been organised by Pfizer Inc. Felix Naughton received consultancy fees from ResMed for a project that he led, designing an app that provided smoking behaviour change advice and connected to a novel inhaled nicotine replacement therapy device, although the company did not/does not make the nicotine device. Peter Sasieni is an unpaid chair of a Trial Steering Committee for Yorkshire Cancer Research (YESS) and holds Cancer Research UK grants and National Institute for Health and Care Research (NIHR) Clinical Trials Unit Support Funding. Lesley Sinclair was awarded funding for the Cessation in Pregnancy Incentives Trial (CPIT).
Funding Information:
The research reported in this issue of the journal was funded by the HTA programme as project number 15/57/85. The contractual start date was in May 2017. The draft report began editorial review in October 2021 and was accepted for publication in September 2022. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HTA editors and publisher have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the draft document. However, they do not accept liability for damages or losses arising from material published in this report.
Funding Information:
This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 13. See the NIHR Journals Library website for further project information.Primary conflicts of interest: Linda Bauld is on the Public Health Research (PHR) Research Funding Board. Peter Hajek received research funding from and provided consultancy to Pfizer Inc. (New York, NY, USA). Hayden McRobbie received honoraria for speaking at smoking cessation meetings and attending advisory board meetings that have been organised by Pfizer Inc. Felix Naughton received consultancy fees from ResMed for a project that he led, designing an app that provided smoking behaviour change advice and connected to a novel inhaled nicotine replacement therapy device, although the company did not/does not make the nicotine device. Peter Sasieni is an unpaid chair of a Trial Steering Committee for Yorkshire Cancer Research (YESS) and holds Cancer Research UK grants and National Institute for Health and Care Research (NIHR) Clinical Trials Unit Support Funding. Lesley Sinclair was awarded funding for the Cessation in Pregnancy Incentives Trial (CPIT).Acknowledgements We thank the trial participants; the staff at participating sites; the members of the TSC and Data Monitoring and Ethics Committee; NIHR research project managers; and the staff of the Barts CTU and the King’s CTU. We are especially grateful to the NIHR Health Technology Assessment programme who provided the main study funding and to Public Health England for providing funding for the study NP supplies.
Funding Information:
uF nin: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment Vol. 27, No. 13. See the NIHR Journals Library website for further project information.
Publisher Copyright:
© 2023 Przulj et al.