The problem of purpose in quality of life research

In this paper I investigate one aspect of the validity of a certain type of subjective assessment of health and illness or as they are sometimes called Health-Related Quality of Life (HRQoL) measures. These assessments are typically a series of questions directed to individual patients in the form of a questionnaire and their aim is to discover the subjective experience of a cohort of people at different times, for instance before and after a surgical intervention. These measurements can be, and often are used in conjunction with clinical assessments to gain information on health outcomes for policy implementation or revision. For example, to determine which hospitals or surgeons are doing well and which ones are doing poorly or to determine which interventions are most effective.