Quality of life assessment: understanding its use as an outcome measure.

The limited available evidence of the effectiveness of many existing and emerging medical practices has led to the realization that health outcome data should be used in the evaluation of health care interventions. Interest in improving health outcome evaluation is increasing as a result of the need to balance the costs and benefits of medical technologies. Measures of health-related quality of life are receiving greater use in clinical studies. Quality of life measurement provides additional data for making clinical and health care policy decisions. In addition, there is growing awareness that in certain diseases, quality of life may be the most important health outcome to consider in assessing treatment efficacy. There are a number of methodological issues that must be considered in conducting or evaluating quality of life research.