Abstract
Good nutrition promotes health-related quality of life (HRQOL) by averting malnutrition, preventing dietary deficiency disease and promoting optimal functioning. However, definitions of quality of life also encompass life satisfaction and both physical and mental well-being. Nutrition and diet have not been a part of mainstream research on quality of life and are not included among key quality of life domains. This article explores connections between diet and nutritional status in relation to HRQOL measures and overall well-being among older adults.
THE goals of this review are fourfold. First, we define terms such as health-related quality of life (HRQOL), functional impairment, and functional status. Second, we describe some common methods for measuring quality of life. Third, we examine some of the relationships between nutrition, nutritional interventions, and HRQOL in older persons. Finally, we provide recommendations for assessing and monitoring nutrition and HRQOL in older adults. This article focuses primarily on diet and nutritional status as they relate to HRQOL and functional status. However, the need for assessing and taking into account other sensory, psychological, and social aspects of food and eating is recognized.
Definitions
Appendix Table 1 provides definitions for such terms as quality of life, functional impairment, functional status, and nutritional status that are used in the article. The term functional status is usually restricted to physical status (as assessed by such measures as the activities of daily living [ADLs] or the Karnovsky Index) (1)(2) and the behavioral competence to carry out very simple tasks that involve cognitive components, such as those in the instrumental activities of daily living (IADLs). Nutritional status is a multidimensional concept that includes dietary, anthropometric, biochemical, and clinical indicators of nutritional health. Thus, nutritional status is essentially a description of medically related characteristics and, as such, the concept is somewhat circumscribed in its focus. It fails to include sensory, psychological, and social aspects of food and eating that may also be important to the individual. Quality of life is also a concept with multiple dimensions that include the subjective sense of physical and/or mental well-being. In its broadest and most inclusive sense, it is sometimes referred to as “life satisfaction.” A more specific and circumscribed use of the term is HRQOL. HRQOL focuses on the changes in physical and mental health dimensions that may occur with disease, aging, or alterations in functional status.
Reasons for Concern
The reasons for measuring HRQOL and functional status are that they provide a means of identifying and monitoring the impact of disease and interventions on the physical and mental health of elderly individuals as they themselves perceive this impact. Health-related quality of life is especially important among older persons because many of them are affected with chronic health problems and therefore traditional indices, such as reduced morbidity, may be less meaningful to them than subjectively assessed symptomatic improvement. Some of the causes of decreased HRQOL may be preventable and others are treatable with appropriate interventions. Thus, the potential for improving quality of life is considerable. Health-related quality of life is also more relevant to the subjective reality of the individual's daily life and to life satisfaction than are traditional measures of morbidity and mortality. Patient perspectives are especially important in chronic diseases since changes in HRQOL occur as the disease waxes and wanes, as well as with advancing age. Health care professionals may forget or fail to inquire about patients' HRQOL and emotional status because other urgent tasks intrude. Short questionnaires that ask about these issues and are incorporated routinely into patient visits can provide information on HRQOL that alerts clinicians to changes that otherwise might go unrecognized. If health-related quality-of-life measurement tools are included in the visit, professionals are more likely to spend time on such issues with patients (3). Medical and scientific technology has sustained and prolonged the lives of many older people. Although life extension is an advance, some older individuals survive but suffer a good deal of discomfort and disability. HRQOL measures help to highlight and quantify these problems, alert health professionals to their occurrence, and may trigger interventions that can ameliorate these problems. HRQOL measures may also help clarify the psychological implications of various interventions and procedures and help in tailoring interventions so that individual well-being is maximized (4).
Dimensions of Quality of Life
Researchers in the social and biomedical sciences conceptualize and use the term “quality of life” differently. The broadest use of the term qualit