A logic model outlining the processes involved in an intervention for smoking cessation during pregnancy

Abstract

Background: Cigarette smoking is a leading preventable factor associated with complications in pregnancy. We developed a text-messaging intervention to promote smoking cessation during pregnancy using narrative and images as modes of delivery. Initial feasibility testing indicates that the intervention is feasible, acceptable and likely to encourage smoking cessation for pregnant women. Aims: To develop a logic model outlining the complex set of constructs necessary for facilitating positive behaviour change. Methods: A literature review was carried out to inform the content of the logic model. This explored; existing psychological theory, evidence-based Behaviour Change Techniques, and inductively derived key intervention ingredients. Qualitative interviews (n=18) were then conducted with stakeholder groups to fill in gaps in the literature. This evidence was collated and a logic model informed by expert opinion was developed. Findings: To achieve the desired outcome of long-term smoking cessation, we found that the key mediating variables are; increased participant self-efficacy and raised risk perceptions. Intervention processes designed to achieve these include; using narrative to embed information, providing a fictional coping model, personalised feedback, skills building, facilitating social support, and using images to increase concreteness. Contextual factors such as midwife engagement in the intervention are also integrated. Discussion: This integrated approach to intervention development increased the clarity and comprehensiveness of the modelling approach. The final logic model demonstrates how a complex set of theoretical components were combined to underpin an intervention and optimise its likelihood of effectiveness.