While the development of modem medicine is associated with both increases in scientific knowledge and. improved outcomes in health care it is also associated with increased uncertainty as expert and lay knowledge bases have diverged and separated. The development of a principal-agent relationship in the late nineteenth and early twentieth century in which medical practitioners used their specialist knowledge to make decisions for and on behalf of their patients provided one way of managing this uncertainty. However the development of a less deferential and more consumerist culture associated with medical scandals in which trust has been betrayed have led to increased regulation of medical practice, especially the development of national standards based on encoded knowledge. Even if governments can overcome the practical problems of using such systems to structure decision-making, because these systems fail to address the personal and emotional components of trust they are likely to create a 'trust deficit,' a system that may work better, but is trusted less.
