This chapter is about how healthcare managers and policymakers use evidence when they make decisions, and it argues that by making more effective use of evidence from research and evaluation, managers and policymakers could make better decisions. It is not difficult to find examples of bad decisions – which not only look like mistakes in retrospect, but which flew in the face of evidence available at the time. For example, mergers between healthcare organisations have often been justified on the grounds that the new, larger organisation would be more efficient, with lower administrative costs and savings from the rationalisation of clinical services, buildings and facilities. In the UK the late 1990s saw an epidemic of acute hospital mergers and reconfiguration based on little or no real evidence (Edwards and Harrison 1999), and more recently the Department of Health has mandated mergers among primary care organisations across England (DH 2005). In fact, the research evidence suggests that such mergers rarely achieve their explicit objectives, that there are often as many diseconomies as economies of scale and that after merger it takes years for the new organisation to become properly integrated and begin to realise any of the potential advantages of its scale (Fulop et al. 2002). There are even a number of well-documented examples of frankly disastrous mergers that have come close to destroying the unfortunate organisations which have been pressed into merging (Kitchener 2002). So why, faced with all this evidence, do managers and policymakers continue to have such faith that organisational mergers 'work'? The unpalatable truth may be that managers do not know about the evidence; do not understand, trust or believe it if they do know it exists; and allow other factors such as ideology, fashion and political convenience to predominate in the decision-making processes in their organisations (Abrahamson 1996; Marmor 2001; Smith et al. 2001).
This chapter first explores the growth of the evidence-based healthcare movement in the 1990s and the increasing role played by research evidence in clinical decision making. It then argues that while managerial