Until recently, post-war health care was characterized first by expansion and later by cost containment. We now appear to have entered a period focusing on assessment and accountability, often described as the outcomes movement. Patients' outcomes are regarded as the most important information on effectiveness and quality. The outcomes movement includes the traditional outcome measures of mortality and morbidity, as well as clinical endpoints, social, mental and physical well-being, general health, quality of life and patient satisfaction. Establishing the effectiveness of medical care in the "real world" is an important aspect of outcomes research. The article discusses the emergence of outcomes research, the central elements of outcomes management, and some critical views on the outcomes initiative.