The authors are a multidisciplinary team of senior and internationally recognised researchers from the Universities of London and Southampton. John Gabbay researches into the way that knowledge enters policy and practice in organisations. Andrée le May is renowned for her work on knowledge in practice. Catherine Pope is a distinguished qualitative methodologist with long experience in ethnographic research in healthcare. Glenn Robert specialises in organisational studies on quality and service improvement and large-scale change in healthcare. Paul Bate is a leading authority on organisational development and change management, including healthcare in the UK and USA. Mary-Ann Elston is a well-known researcher and teacher in medical sociology.

"This is an absorbing visit behind the scenes of the implementation of a major healthcare innovation. At a time when health systems face unprecedented change, here and overseas, this study makes salutary reading for those who promote change and for those whose task is to deliver it. To help, the authors offer a very useful synthesis of the learning from this study and the wider innovation evidence base. Well worth reading." Bernard Crump, NHS Institute for Innovation and Improvement, University of Warwick

• Introduction; Transplanted roots - where the innovation came from; Fertile ground? The organisational milieux of the treatment centres; Taking up the challenge: local motives for the innovation; The impact of the wider policy context; Achieving the goals? How and why the treatment centres evolved; Improving practice? Evidence of innovative ways of working; Summary and conclusions: making sense of what happened; Implications for policy, practice and research.