The relationship between quality of life and health

 Despite the ambiguity in the conceptualization of quality of life, some researchers have developed conceptual models in an attempt to describe the relationships between quality of life and health. These models generally imply that the presence of disease results in symptoms that affect various so-called dimensions of quality of life, such as physical, psychological, and social functioning, which in turn contribute to overall quality of life.    Most models also account for the presence of a variety of psychological processes and social, cultural and environmental factors. For example, Wilson and Cleary described a model wherein physiological and psychological symptoms affect functional status, which affects general health perceptions and quality of life. Concepts pertaining to characteristics of the individual (e.g., motivation and values) and characteristics of the environment (e.g., social support) were also included in their model.
 Other researchers have sought to provide empirical support for similar models of the relationship between health and quality of life. Based on a meta-analysis of studies that used instruments measuring various health status indicators, Smith, Avis, and Assmann showed that variation in quality of life was explained by variables pertaining to various life domains, which were affected by differences in physiological health status (e.g., the presence of disease) and symptom severity. Examples of life domains in their meta-analysis include variables that reflected psychological, social, or physical functioning. Quality of life was represented by measures of life satisfaction, wellbeing and single-item quality of life indicators. Thus, their “model of the determinants of quality of life” is based on the proposition that the life domains mediate the degree to which quality of life is explained by differences in symptom severity and physiological health status.