Improving effectiveness of nicotine replacement therapy for smoking cessation in pregnancy through better adherence and adequate dosing.

Aims, objectives and questions We aim to evaluate how the NHS can support pregnant smokers to effectively and safely use nicotine replacement therapy (NRT) for smoking cessation. We plan to develop a complex intervention to help pregnant quitters better titrate the nicotine from NRT to suit their needs and to assess whether this increases adherence to NRT, smoking cessation rates and cost effectiveness of NHS cessation support. Key research questions Workstream (WS1): Identifying intervention messages How can NRT be used safely in pregnancy? What are pregnant smokers concerns about NRT and how can health professionals respond? What are the barriers against and facilitators for integrating professionals responses into routine practice? WS2: Intervention feasibility of delivery, refinement and evaluation How can WS1messages be integrated into a complex intervention? How can delivery of this intervention to pregnant smokers be optimised? What is the most objective way to measure pregnant quitters adherence to NRT? Can health professionals be trained to deliver the complex intervention? WS3: Impact on adherence to NRT Does the intervention safely increase pregnant smokers adherence to NRT, demonstrating feasibility for improving smoking cessation rates? WS4: Impact on smoking cessation Is the intervention effective and cost effective for promoting smoking cessation amongst pregnant smokers who use Stop Smoking Service Support? Background and rationale Smoking in pregnancy is a massive cause of morbidity and mortality and stopping smoking reduces health inequalities. In the UK, 26% of pregnant women smoke and NRT is offered to all who seek support with stopping. Although NRT is effective outside of pregnancy, our systematic review shows this has only borderline efficacy in pregnancy; this lack of efficacy is explained by pregnant quitters poor adherence to NRT. Our qualitative work shows pregnant smokers who have been prescribed NRT have substantial safety concerns and so underuse this. We have also shown that pregnant smokers have accelerated nicotine metabolism and so quitters need more NRT to generate sufficiently high blood nicotine concentrations to control symptoms of tobacco withdrawal. This suggests that for NRT to help pregnant quitters stop, they need to use more NRT at higher doses than non-pregnant quitters ; four secondary analyses of data from our large NRT trial are consistent with this hypothesis. In four work streams (WS) we develop and test a combined behavioural and pharmacological complex intervention to improve NRT adherence and also cessation rates. Research Plan WS1: Key messages for behavioural intervention components are derived using reviews of NRT safety and of pregnant smokers concerns about nicotine; qualitative work with cessation advisors and pregnant smokers; PPI input and an expert group. WS2: A prototype intervention combining behavioural and pharmacological approaches will be developed and delivered to sequential cohorts of pregnant smokers (n=10) from whom we will seek feedback. Based on previous work, the pharmaceutical component will involve providing dual NRT - a longer acting NRT (e.g. patch) together with a shorter acting one (e.g. inhalator). We will investigate how to collect objective and complete NRT adherence data by comparing the amount of NRT used with usage reported by text message, phone and questionnaires, finalising outcome measurement for a trial. WS3: An RCT enrolling 200 pregnant smokers will test whether the intervention improves NRT adherence, monitoring the impact on nicotine exposure. WS4: In a full within-trial pilot we will assess the feasibility of training SSS staff in intervention delivery and of all other trial methods. The subsequent full trial will be a cluster-randomised, stepped-wedge RCT (sample size = 2550 pregnant quitters ) in which the intervention is introduced at a service-level into 25 SSS; the primary out