The problem of deciding which health care technologies to evaluate is urgent. With new technologies proliferating alongside steadily increasing health care costs, it is critical to discriminate among technologies to direct tests and treatments at those who can benefit the most. Given the vast number of clinical problems and technologies to be evaluated, the many months of work required to study just one problem, and the relatively few clinicians with highly developed analytic skills, institutions must set priorities for assessment. This book sets forth criteria and a method that can be used by public agencies such as the Office of Health Technology Assessment (in the U.S. Public Health Service) and by any private organization conducting such work to decide which technologies to assess or reassess.