Key Concepts

Quality of life is an individual's satisfaction or happiness with life in domains he or she considers important¹. Historically known as "life satisfaction" or "subjective well-being," it is now sometimes referred to as "overall quality of life" or "global quality of life" to distinguish it from "health-related quality of life." It is the broadest of all concepts we are concerned with, being influenced by all of the dimensions of life that contribute to its richness and reward, pleasure and pain. These dimensions include, but are not limited to, health. A person's assessment of satisfaction with life involves two subjective considerations: how important a given domain is for that person, and how satisfied one is with that domain. One can be unsatisfied with a domain that one considers to be of relatively little importance, and thus maintain a satisfactory overall quality of life. Dissatisfaction with a domain of great importance to an individual, however, would clearly contribute to lower overall life quality. Numerous taxonomies of life domains have been proposed by social, psychological, gerontological, and health sciences researchers based on studies of general populations of both well and ill people. A typical taxonomy is that of Flanagan², which categorizes 15 dimension of life quality into five domains, as shown in Table 1.

Physical and material well-being	Material well-being and financial security Health and personal safety
Relations with other people	Relations with spouse Having and rearing children Relations with parents, siblings, or other relatives Relations with friends
Social, community, civic activities	Helping and encouraging others Participating in local and governmental affairs
Personal development, fulfillment	Intellectual development Understanding and planning Occupational role career Creativity and personal expression
Recreation	Socializing with others Passive and observational recreational activities Participating in active recreation

Table 1: Flanagan's Domains of QOL

Note that health (#2) is one of many dimensions contributing to overall quality of life in Flanagan's taxonomy. The World Health Organization defines health as "not merely the absence of disease or infirmity"³ but as a concept that incorporates notions of well-being or wellness in all areas of life (physical, mental, emotional, social, spiritual). Health, according to this definition, is a broad concept that subsumes the related concepts of disease, illness, and wellness. When considered as a dimension or domain of quality of life, however, health is best thought of in the narrower sense of factors that are generally considered to fall under the purview of health care providers, or that are likely to be the target of a health care intervention.