Since 1948, when the World Health Organization defined health as being not only the absence of disease and infirmity but also the presence of physical, mental, and social well-being,1 quality-of-life issues have become steadily more important in health care practice and research. There has been a nearly exponential increase in the use of quality-of-life evaluation as a technique of clinical research since 1973, when only 5 articles listed “quality of life” as a reference key word in the MEDLINE data base; during the subsequent five-year periods, there were 195, 273, 490, and 1252