The focus of assessment of disease impact is moving beyond survival and biomedical outcomes to include a comprehensive set of health status and quality of life concepts. We have discussed four socially relevant concepts that can be thought of as dimensions of health status or well being: physiologic status, personal (physical) functioning, mental health, and social well-being. Quality of life was also discussed briefly as a very global concept encompassing these health status dimensions and a broader set of concepts including finances, housing, and employment. Five categories of measures based on manifest content were also discussed, including measures of disease/diagnostic status, personal functioning, mental health, general health perceptions, and social/role functioning. The physiologic dimension of health is very heterogeneous and includes many concepts and measures that vary largely independently of each other and that differ in terms of their impact on the other dimensions of health status. The physical, mental, and social dimensions of health and well-being also can be measured many different ways, and each can be broken down into distinct concepts that may vary in importance from one study to another. Of these three concepts, social well-being is the most heterogeneous. To assist investigators searching for valid measures of specific health status and quality of life concepts, we recommended formal estimations of measurement models. A preliminary model of 15 health status measures was presented to illustrate the usefulness of such a model.