Methods in outcomes research in hepatology: definitions and domains of quality of life.

The health care system in the United States is at a turning point. We are experiencing a shift in focus from structure and process to outcomes, and from specific clinical outcomes to generic outcomes. It is no longer sufficient to document where and how care is delivered and what clinical indicators were changed through various interventions. Rather, payers, employers, and patients themselves demand evidence that the health care system produces patients who feel better, can do more, and are confident about their health. These concepts, collectively referred to as Health-Related Quality of Life (HQL), are an important aspect of the natural history of liver diseases and an important means of assessing the results of therapeutic interventions.