Evidence-based decision making: when should we wait for more information?

We discuss the challenge of managing innovation in and access to health care interventions in an evidence-based, cost-effective way, and we describe a decision-making framework (using U.S. and U.K. case studies) for health care payers considering the adoption of new technologies. We argue that providing reimbursement for what could be a cost-effective technology "only in the context of research" will be appropriate if the costs of delaying implementation are offset by the value of "keeping one's options open" by waiting for more information. We conclude that there is a need for better integration of health care decision-making processes with research policies.