Historical and methodological perspectives on cancer outcomes research.

Outcomes research is the study of the net effects of the health care process on the health and well-being of individuals and populations. It encompasses a wide breadth of issues, including measurement of patient preferences and health status, broadly referred to as quality of life. Evaluation of health-related quality of life in research studies has been facilitated by the development of a number of measurement tools. In addition to general health tools, cancer-related tools are available, some of which include cancer site-specific or symptom-specific measures. Preference assessment, from the perspective of the patient or general population, is necessary to incorporate quality of life into economic analyses. Various techniques are available to assign preference values to outcomes; metrics such as quality-adjusted life-years (QALYs) are then used to combine quality and quantity of life into a usable value for economic analyses. In the future, quality of life and economic measurements should be incorporated into phase III trials, effectiveness trials, and observational studies.