This series was originally instigated by the NHS Management Executive Purchasing Unit of the Department of Health to provide purchasers with basic information on major diseases and health care issues. However, it also contains vital information for clinicians and academics. Each chapter consists of an analysis of issues, epidemiological summaries, summaries of current services, assessments of the cost-effectiveness of interventions; and each suggests a model of care, outcome measures, targets, information and research requirements. Volumes One and Two review 20 important conditions and services which cover over one third of the burden diseases in most western countries and, in particular, select those where there is urgent scope for reviewing current services. Each chapter analyzes its topic and reviews evidence, prevalence, the range of services available and the effectiveness of those services. Drawing this information together and exploring the evidence, each author sets an agenda for change. Both the evidence and the agenda should be useful to health-care purchasing authorities whose principal remit is to buy services so as to meet the health-care needs of the population. Their work needs to be knowledge-based, and these volumes set out to provide a firm foundation on which to build that knowledge.