Using comparative effectiveness research to inform policy and practice in the UK HHS: past, present and future.

Health systems that have fixed budgets and a coherent organizational structure generally have found it valuable to have a dedicated primary research capacity to answer decision-oriented value-for-money questions of particular importance to the system. The UK NHS is one example of such a system. Here, we review the historical evolution of building comparative effectiveness research (CER) capacity in the NHS, describe the current situation, with a focus on how this research is used to inform decisions, and discuss present and emerging challenges. We draw some possible lessons for the US, which is currently considering using CER to inform healthcare policy and practice decisions.