Overview of health-related quality-of-life measures.
Quality of life (QOL) as a measurable health-care outcome is discussed, and an overview of the field of QOL assessment is provided. QOL assessments can be used to evaluate drugs in clinical trials, to evaluate provider performance, and to monitor the progress of patients receiving drug therapy. QOL information is most useful in evaluating drug therapy when the primary purpose of a drug is palliative rather than curative, when a drug is somewhat effective but also fairly toxic, when lifelong therapy is administered to prevent complications of a relatively asymptomatic disease, and when there are several equally effective therapies for a specific condition but the adverse-effect profiles differ. Contemporary QOL questionnaires are completed by patients, and they most commonly include dimensions of physical function, mental or cognitive function, emotional or psychological function, social and role function, disease symptoms, and perceptions of well-being. The keys to successful QOL assessment in clinical practice will be selection of instruments that are practical to administer and are capable of detecting small changes in health, selective application of those instruments to patient populations most likely to benefit from this more intensive form of monitoring, and efficient use of data management systems. The consumer of QOL literature must assess the validity of QOL data obtained in a given study and their applicability to his or her practice setting.