Understanding the influence of evidence in public health policy : what can we learn from the tobacco wars

Public health is overtly policy-orientated and there is widespread support for the notion that health policies should be strongly informed by evidence. Despite this, studies consistently find that public health policies are not evidence-based. This is often explained by reference to popular theories about research-policy relations which highlight, amongst other things the communicative gaps between academics and policymakers, the centrality of values (or politics) to decision-making and the efforts by external interests to influence policy outcomes. Employing the ‘tobacco wars’ as a case study, with a particular focus on the UK, this paper explores how tobacco control advocates and tobacco industry interests have attempted to influence policy and how, in so doing, each has sought to enrol evidence. Whilst accepting that evidence has played an important role in tobacco policy development, the paper challenges claims that the implementation of tobacco control policies can be attributed to evidence. Turning to value-orientated and network-based approaches to conceptualising policy development, the paper demonstrates both the importance of values and the complex nature of coalitions. However, it argues that this approach needs to be supplemented by an ideational understanding of policy-change which pays attention to the ways in which arguments and evidence are constructed and framed. The paper also suggests there are signs the two, ‘coalitions’ involved in the ‘tobacco wars’ may be unravelling. Overall, the ‘tobacco wars’ serve to highlight the complex relationship between evidence and policy, offering some insights for those interested in studying or improving the use of evidence in policy