Measuring quality of life in evaluating clinical interventions: an overview.

Health professionals provide care with some purpose in mind. It is reasonable to assume that they are therefore interested in observing and measuring health outcomes. In the recent past, it has become fashionable to describe health outcomes in terms of their impact on 'quality of life', a widely used term that is usually left undefined. Measures of health-related quality of life (HRQoL) are now in common usage in clinical studies. The construction of both generic and condition-specific measures of HRQoL relies heavily on the choice of descriptive domains, a process that often reflects the personal values of the developer of the instrument. Subjective valuation is a recurring phenomenon in the construction and application of HRQoL measures. These values should not be restricted to the private judgement of the clinician alone. The challenge for those evaluating clinical interventions is to make such values explicit and to extend the franchise to society as a whole.