This paper describes the work of the Research Unit of the Royal College of Physicians on clinical effectiveness and links with other national initiatives. The overall goal is to improve the quality of care by basing routine care on research evidence, an approach referred to as the 'bridge for health'. Systematic reviews bring together research evidence and are largely carried out by the Cochrane Collaboration, the NHS Centre for Reviews and Dissemination and the NHS Health Technology Assessment programme. Clinical guidelines, now produced according to a more rigorous methodology, are used to package research to support decisions about health care by clinicians, patients and others. Clinical audit, along with outcomes development, is carried out at a national level to support the implementation of clinical guidelines by clinical teams in local health services. To achieve this, it matches the best principles of quality improvement. Future identified trends in clinical effectiveness include a greater emphasis on better integration of effort and exchange of best practice.