A behaviour change intervention to reduce home exposure to second hand smoke during pregnancy in India and Bangladesh: a theory and evidence-based approach to development.

BACKGROUND Home exposure to secondhand smoke (SHS) is highly prevalent amongst pregnant women in low- and middle-income countries like India and Bangladesh. The literature on the efficacy of behaviour change interventions to reduce home exposure to SHS in pregnancy is scarce. METHODS We employed a theory and evidence-based approach to develop an intervention using pregnant women as agents of change for their husband's smoking behaviours at home. A systematic review of SHS behaviour change interventions led us to focus on developing a multicomponent intervention and informed selection of behaviour change techniques (BCTs) for review in a modified Delphi survey. The modified Delphi survey provided expert consensus on the most effective BCTs in reducing home exposure to SHS. Finally, a qualitative interview study provided context and detailed understanding of knowledge, attitudes and practices around SHS. This insight informed the content and delivery of the proposed intervention components. RESULTS The final intervention consisted of four components: a report on saliva cotinine levels of the pregnant woman, a picture booklet containing information about SHS and its impact on health as well strategies to negotiate a smoke-free home, a letter from the future baby to their father encouraging him to provide a smoke-free home, and automated voice reminder and motivational messages delivered to husbands on their mobile phone. Intervention delivery was in a single face-to-face session with a research assistant who explained the cotinine report, discussed key strategies for ensuring a smoke-free environment at home and practised with pregnant women how they would share the booklet and letter with their husband and supportive family members. CONCLUSION A theory and evidence-based approach informed the development of a multicomponent behaviour change intervention, described here. The acceptability and feasibility of the intervention which was subsequently tested in a pilot RCT in India and Bangladesh will be published later.