Quality of life assessment involves a class of measurements fundamental to many aspects of health care planning and outcomes research. It is relevant for associating symptoms, adverse reactions of treatment, disease progression, satisfaction with care, quality of support services unmet needs and appraisal of health and health care options. Quality of life measures that do not consistently distinguish between groups are often only weakly related to objective criteria and show little convergence across measurements perspectives. Differences in quality of life appraisal are part of human adaptation and inherent in all quality of life measurements. This book presents current research in health-related quality of life, with a particular focus on disease and drugs.