Abstract
Background: Smoking during pregnancy is a global public health issue and one of the most modifiable risk factors for adverse pregnancy outcomes. Complications from continued smoking include miscarriage, preterm birth, low birth-weight and still-birth. In Warwickshire, rates of smoking in pregnancy vary from above the national average in the north of the region, to below the national average in the south. The Warwickshire Stop Smoking in Pregnancy Service (SSiPS) has good quit rates but has problems with low engagement. Behavioural science research can provide theoretical understanding of why behaviour occurs, in order to implement strategies to elicit positive behaviour change.Methods: The aim of this thesis was to design an intervention which addressed rates of smoking in pregnancy in Warwickshire. As a complete behaviour system and framework for intervention design, the Behaviour Change Wheel(BCW), the COM-B model (Capability, Opportunity, Motivation –Behaviour), Theoretical Domains Framework (TDF) and Behaviour Change Technique (BCT) v1 taxonomy (BCTTv1) were chosen for guiding intervention development. Three parallel studies were carried out to inform decision-making about the target behaviours of the intervention. These included a systematic review and meta-analysis, to explore the effectiveness of digital interventions for increasing smoking cessation in pregnancy, and two qualitative needs analysis studies, which were structured around the TDF and COM-B. The first investigated the barriers and facilitators to supporting pregnant women to stop smoking. The second explored the barriers to, and facilitators of, stopping smoking in pregnancy and engaging with cessation support from the viewpoint of women who had smoked during their pregnancy, midwives and Stop Smoking in Pregnancy advisors. Data from face-to-face and telephone interviews were analysed using thematic analysis to underpin intervention development. Steps of the BCW were followed to design the intervention, which was tested in an acceptability study implementing think aloud methodology.
Results: The systematic review and meta-analysis found that digital interventions are effective for increasing smoking cessation in pregnancy, particularly computer-based and text message programmes. Seven behaviour change techniques (BCTs) were associated with intervention effectiveness, including ‘Information about antecedents’ and ‘Action planning’, with interventions implementing larger numbers of BCTs appearing to produce the greatest effects. From the needs analyses, a list of possible behaviours for the intervention to address were rated for capacity for change and likely impact on other behaviours, particularly for pregnancy smoking cessation. The behaviours offering the most promise for the intervention were selected as engaging with the Stop Smoking in Pregnancy Service (SSiPS) after referral and continuing to engage with the service. Key barriers to accessing support were found to include a lack of awareness of the service, pressure to quit smoking completely, change of intentions to quit, and considerable social influences and misconceptions about smoking in pregnancy. The BCW was used to map analysed data to intervention functions, policy categories and BCTs. Intervention content was then developed in collaboration with key stakeholders, to produce a multi-component intervention. A script was provided for midwives to help them broach the subject of smoking and to promote the SSiPS. Alongside the script, midwives would also provide women being referred to the SSiPS with a lip balm, to encourage pregnant smokers to engage with the service and to use the service website. The existing SSiPS website was extensively improved to address barriers to smoking cessation and engaging with cessation support. Existing SSiPS text messages were amended and added to, in order to further encourage access to the service and provide support between appointments. In addition, advisors are to ask women at the end of their first SSiPS appointment if they feel ready to quit and to commit to attending another session with their advisor. The acceptability study found that service-users and SSiPS advisors held generally positive views of the intervention components, suggesting areas for improvement which were fed back into the intervention design.
Discussion: This thesis has identified that digital interventions are effective for smoking cessation in pregnancy, isolating specific components associated with effectiveness. The research has produced an innovative, evidence-based intervention, which aims to improve the existing care pathway for pregnant smokers by increasing engagement with an already effective service. This intervention addresses uniquely identified barriers, including change of intentions to quit smoking and to engaging with cessation support. Involving stakeholders and service-users at each step of the design has helped to ensure optimal engagement with the intervention, enabling a smooth transition into routine care.
| Date of Award | Sept 2019 |
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| Original language | English |
| Awarding Institution |
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| Sponsors | Public Health Warwickshire |
| Supervisor | Katherine Brown (Supervisor), Emily Fulton (Supervisor), Felix Naughton (Supervisor) & Susan Wild (Supervisor) |