Principles and problems in the assessment of quality of life in health care.
A remarkable surge in efforts to assess the quality of life of patients has occurred in recent years in medical research. Philosophical discussions of these developments have focused, on the one hand, on epistemological reservations about the plausibility of measuring quality of life and, on the other hand, on moral and ethical qualms about the meaning of life conveyed in such assessments. Whilst providing an important note of caution, such critiques fail to recognise two basic principles of quality of life in medical research. Firstly, it is intended to provide understanding about groups and categories of patients rather than individuals. Secondly the purpose of such research is to produce generalisations about the relative costs and benefits of specific health care interventions rather than absolute judgements regarding the quality of life of patients per se. Selecting a good quality of life measure for a clinical trial requires balancing criteria such as validity with practical feasibility. Such measures will play an increasingly central role in providing research evidence to improve health care.