Contextual influences on the role of evidence in e-cigarette recommendations: a multi-method analysis of international and national jurisdictions

Background: E-cigarette policy has varied across jurisdictions, contrasting with the previous coordinated approach of international tobacco control communities. Aims and objectives: A multi-method case study approach was used to understand the role of evidence and external and internal contextual factors in the development of public health recommendations across four purposively selected jurisdictions (WHO, UK, Australia and USA). Methods: Informed by Dobrow et al's (2004) conceptual framework for context-based evidence based decision making, four data sources were drawn upon: 1) 15 public health bodies' e-cigarette recommendation documents; 2) seven development documents produced by the public health bodies; 3) sources of evidence cited in the public health bodies' recommendation documents; and 4) 15 qualitative interviews with experts. Thematic analysis and citation analysis were conducted to aid triangulation of evidence. Findings: We found a complex interplay between internal and external factors which influence the role and use of evidence in the development of e-cigarette recommendations. For example, recommendation documents' remit (internal factor) was influenced by various external factors such as epidemiology and policy history, with decisions made over time having reshaped the external context. Considering the findings with respect to evidence utilisation, we propose a modified version of Dobrow et al's (2004) framework, highlighting the important interplay between internal and external contextual factors. Discussion and conclusion: This research suggest internal and external contextual factors mutually interact and influence how evidence is incorporated into recommendations. This dynamic interplay of contextual factors may help explain why different policy approaches are pursued concerning public health topics, particularly e-cigarettes.