Evidence and the health policy process: from traditional evidence hierarchy to inclusive and multi-source methodology

Abstract

Calls for evidence-based health policy have gathered force as an extension of the movement for evidence-based medicine. In clinical medicine, major investment has been made in efforts to systematize the collection and analysis of data and distinguish effective interventions from those that are less likely to work. In contrast, there is little consensus on what data are needed and what research methods are suitable and acceptable to produce a robust evidence base for social policy in the health sector. Evidence gathering for health policy must synthesise diverse sources, recognise the extent to which context influences policy outcomes, accommodate potentially conflicting interests and be flexible enough to respond to the time and resources pressures that are at play. Despite the challenges, there is scope for the development of a methodology that can draw on a wide range of evidence sources while retaining sufficient scientific rigour. These sources should extend from data generated using causal methods (randomized controlled trials) to information that can shed light on the many contextual and political issues that are also pertinent to health policy decision making.