The purpose of this book is to provide information about what works -- specifically, the cost-effectiveness of health interventions in a variety of settings. Such information should influence the redesign of programs and the reallocation of resources, thereby helping to achieve the ultimate goal of reducing morbidity and mortality. As was the case with the first edition, this second edition of Disease Control Priorities in Developing Countries will serve an array of audiences. This second edition of Disease Control Priorities in Developing Countries (DCP2) seeks to update and improve guidance on the what-to-do questions in DCP1 and to address the institutional, organizational, financial, and research capacities essential for health systems to deliver the right interventions. DCP2 is the principal product of the Disease Control Priorities Project, an alliance of organizations designed to review, generate, and disseminate information on how to improve population health in developing countries. In addition to DCP2, the project produced numerous background papers, an extensive range of interactive consultations held around the world, and several additional major publications.