How do tobacco control policies work in low-income and middle-income countries? A realist synthesis

BACKGROUND: The burden of tobacco use is disproportionately high in low- and middle-income countries (LMICs). There is scarce theorisation on what works with respect to implementation of tobacco control policies in these settings. Given the complex nature of tobacco control policy implementation, diversity in outcomes of widely implemented policies and the defining role of the context, we conducted a realist synthesis to examine tobacco control policy implementation in LMICs. METHODS: We conducted a systematic realist literature review to test an initial programme theory developed by the research team. We searched EBSCOHost and Web of Science, containing 19 databases. We included studies on implementation of government tobacco control policies in LMICs. RESULTS: We included 47 studies that described several contextual factors, mechanisms and outcomes related to implementing tobacco control policies to varying depth. Our initial programme theory identified three overarching strategies: awareness, enforcement, and review systems involved in implementation. The refined programme theory identifies the plausible mechanisms through which these strategies could work. We found 30 mechanisms that could lead to varying implementation outcomes including normalisation of smoking in public places, stigmatisation of the smoker, citizen participation in the programme, fear of public opposition, feeling of kinship among violators and the rest of the community, empowerment of authorised officials, friction among different agencies, group identity among staff, shared learning, manipulation, intimidation and feeling left out in the policy-making process. CONCLUSIONS: The synthesis provides an overview of the interplay of several contextual factors and mechanisms leading to varied implementation outcomes in LMICs. Decision-makers and other actors may benefit from examining the role of one or more of these mechanisms in their particular contexts to improve programme implementation. Further research into specific tobacco control policies and testing particular mechanisms will help deepen our understanding of tobacco control implementation in LMICs. PROSPERO REGISTRATION NUMBER: CRD42020191541.