Synonyms

Quality of life

Definition

In 1948, the World Health Organization defined health as “the state of complete physical, mental and social well-being and not merely the absence of disease or infirmity” (World Health Organization [WHO], 1948). Since then, QoL has become increasingly important in health-care practice and research. The term “health-related quality of life” (HRQoL) narrows QoL to aspects relevant to health. However, HRQoL is a comprehensive and complex concept for which no universally accepted definition is available (Fayers & Machin, 2000). Two aspects of HRQoL are central in most definitions. First, it is a multidimensional concept that can be viewed as a latent construct which describes the physical, role functioning, social, and psychological aspects of well-being and functioning (Bullinger, 1991; Calman, 1987; Spilker, 1990). Second, in contrast to QoL, HRQoL can include both objective and subjective perspectives in each domain (Testa & Simonson, 1996). The objective assessment focuses on what the individual can do, and it is important in defining the degree of health. The subjective assessment of QoL includes the meaning to the individual; essentially it involves the translation or appraisal of the more objective measurement of health status into the experience of QoL. Differences in appraisal account for the fact that individuals with the same objective health status can report very different subjective QoL.

HRQoL as an Outcome

It has become clear in the last decade that HRQoL is an important outcome variable on its own independent of medical outcomes. HRQoL outcomes can guide decisions on alternative treatments or effectiveness of interventions at a patient group level (Koot, 2001). In clinical research trials in children, HRQoL has long been neglected as an outcome, but this changed rapidly over the last 10 years (Clarke & Eiser, 2004). An important step towards a more structured and frequent use of patient-reported outcomes (PROs) in drug development is represented by the US Food and Drug Administration (FDA) guidance, issued in 2006. This describes how the FDA evaluates PROs, including HRQoL, to be used as effectiveness end points in clinical trials (U.S. Department of Health and Human Services, 2006). This guidance emphasizes the importance of considering HRQoL separate from medical effectiveness. From the individual patient perspective, HRQoL can guide the choice of best treatment, made by the patient himself/herself and the health-care professionals (Koot, 2001). Evaluating the impact of diabetes on the adolescents’ HRQoL and vice versa can help both the patient and physician decide on the optimal individual treatment (de Wit et al., 2008).

HRQoL in Children

Attention to the QoL of children has evolved rapidly from the 1980s. Advances in medical care have changed the emphasis in pediatric medicine from the diagnosis and management of infectious disease to prevention and control of chronic conditions. This means that health-care professionals should have insight into the child's views and experiences. Early attempts to rate children’s QoL were based on data provided by mothers as children are often regarded as unreliable respondents. However, children and parents do not necessarily share similar views about the impact of illness. As children grow older and develop their own life, the HRQoL reports of parents become of less relevance. It has been shown that parents and children agree more on objective domains of HRQoL (i.e., physical functioning) than on subjective domains, like emotional and social functioning (Eiser & Morse, 2001; Janse, Sinnema, Uiterwaal, Kimpen, & Gemke, 2008). Therefore, the child’s HRQoL is included more and more in decisions about their care and treatment.

Cross-References

Quality of Life

Quality of Life: Measurement