Outcomes research in oncology: history, conceptual framework, and trends in the literature.

"Outcomes research" is a commonly used term, but what does it really mean? In this review article, we 1) briefly review the historic background of outcomes research, paying particular attention to the social and political movements that helped shape the field; 2) present a conceptual framework to help classify the major areas of research and provide a working definition of outcomes research; and 3) review the oncology literature in the English language from 1966 through 1998 to examine temporal trends and characterize the body of work being presented to the practicing oncology community. We conclude that outcomes research is a broad concept, which, in its current usage, describes an array of distinct types of research. However, common themes are apparent when outcomes research is viewed in the context of its historic origins and is contrasted with other established disciplines, especially clinical trials. Our literature review shows that outcomes studies are increasing in absolute numbers, in relative proportion of the oncology literature, and in quality. We suggest that as different branches of investigation develop their own literature and methodology-in effect, outgrowing the generic label of outcomes research-they become identified by separate, more precise terms.