Health policy and the politics of evidence

National decisions on the drugs, treatments and medical devices that should be funded through public expenditure are a fundamental element of health policy. But despite a political emphasis upon evidence-based policy, the results of rigorous clinical trials and statistical modelling techniques rarely speak for themselves. So, does the pre-eminence traditionally accorded to quantitative data in the medical field underpin policy decisions on a consistent basis? Or are more subtle, less transparent characteristics of context and interaction evident in the shaping of attendant decisions? This article considers these questions by drawing on a study of decision-making in the National Institute for Health and Clinical Excellence (NICE)-an organization established by the British government in 1999 to decide whether selected health technologies should be made available throughout the National Health Service in England and Wales. In broad terms, the findings point to the primacy of arguments based on quantitatively oriented, experimentally derived data but also to a discursive hegemony of clinicians and health economists in mediating, including or debarring more qualitative, experientially based evidence. A more complex, dynamic understanding of policy governance in the field of health technology appraisal-founded on a discursive appropriation of the idea of the "common good"-goes some way to explaining the persistence of this hegemony despite an avowedly inclusive, plural approach to decision-making.