BACKGROUND The seminal work in the 1970s by Geoffrey Rose on population-based strategies for prevention 1 and Julian Tudor Hart on evidence-based anticipatory care 2,3 had a profound influence on primary care and were actively supported by the Royal College of General Practitioners. In 1985 in the East London borough of Tower Hamlets, five GP practices collaborated as the Healthy Eastenders Project to support a basic electronic health record (EHR) system, employing nurses for preventive activities and providing comparative audits of their care. By 1992, with the first wave of general practice computerisation, a single EHR system, Egton Medical Information Systems (EMIS), was deployed across all practices in Tower Hamlets with the neighbouring boroughs of City and Hackney and Newham following closely. The Clinical Effectiveness Group (CEG) began to form a supportive network for implementing and evaluating work on preventive care across the locality. 4 The early system required 'floppy disks' to extract data using Morbidity Information Query and Export Syntax (MIQUEST) with manual transport, usually by bicycle, to the CEG office to collate information from each practice. Although cumbersome, the results were transformative, and for the first time practices could see their own performance and share comparable information with their peers. 4-6 In the early days, the theoretical framework used by the CEG team to translate evidencebased innovation into routine clinical practice was necessarily pragmatic. With increasing experience, two complementary strategies framed the process of change. The first included elements of change management described by Kotter. 7 These included: building the case for change, forming a coalition that includes both clinicians and managers, empowering others to act on the programme by the provision of education, comparative performance data, and quality improvement tools, creating early wins for the programme, and consolidating the new approach into work-as-usual to ensure sustainability. An early example of this approach was engaging all practices to code self-reported ethnicity in the early 1990s. Working in an area where 50% of registered patients are from ethnic minority groups, the importance of understanding inequalities in access to health services Debate & Analysis