Abstract
The role of evidence and expertise in policy-making has been of interest to public health professionals and political scientists alike. The public health community often sees its efforts as part of a linear knowledge transfer process and tends to blame itself for inadequate communication or translation of its arguments to policy-makers' language when its efforts fail. Political science, especially theories of the policy process, offer alternative perspectives to explain the success or failure of experts' preferred policy goals. This paper focuses on the concept of epistemic communities (groups of experts with a common policy goal derived from their shared knowledge) in policy-making, drawing on examples from the field of health technology assessment in Europe. By combining the parsimony and the central focus on experts of the linear knowledge transfer model with the recognition of complexity of political science, the epistemic communities concept provides a useful structure for the public health community to analyze its efforts to influence policy.