ABSTRACT
It is generally agreed that in order to preserve a good quality of life, one needs to assure a healthy “state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity,” as was stated in the constitution of the World Health Organization (WHO, 1946). Some investigators collect health-related quality of life (HQL) data by determining how well individuals perform on tests of physiologic activities of daily living, mental health functioning, and emotional functioning. Others feel that HQL is intrinsically a perceptual issue that requires assessment by a clinical investigator, caregiver, or participant using questionnaires. The increase in attention to HQL within the pharmaceutical industry has predominantly focused on the latter approach, resulting in the rapid proliferation and application of HQL questionnaires to drug development.
