Why is quality of life of important?
Quality of life is important to everyone. Although the World Health Organization (WHO) defined health very broadly as long as a half century ago, health in the United States has traditionally been measured narrowly and from a deficit perspective, often using measures of morbidity or mortality. But, health is seen by the public health community as a multidimensional construct1 that includes physical, mental, and social domains.
As medical and public health advances have led to cures and better treatments of existing diseases and delayed mortality, it was logical that those who measure health outcomes would begin to assess the population’s health not only on the basis of saving lives, but also in terms of improving the quality of lives.
What is quality of life?
Quality of life (QOL) is a broad multidimensional concept that usually includes subjective evaluations of both positive and negative aspects of life.2 What makes it challenging to measure is that, although the term “quality of life” has meaning for nearly everyone and every academic discipline, individuals and groups can define it differently. Although health is one of the important domains of overall quality of life, there are other domains as well—for instance, jobs, housing, schools, the neighborhood. Aspects of culture, values, and spirituality are also key domains of overall quality of life that add to the complexity of its measurement. Nevertheless, researchers have developed useful techniques that have helped to conceptualize and measure these multiple domains and how they relate to each other.
What is health-related quality of life?
The concept of health-related quality of life (HRQOL) and its determinants have evolved since the 1980s to encompass those aspects of overall quality of life that can be clearly shown to affect health—either physical or mental.3-6
- On the individual level, HRQOL includes physical and mental health perceptions (e.g., energy level, mood) and their correlates—including health risks and conditions, functional status, social support, and socioeconomic status.
- On the community level, HRQOL includes community-level resources, conditions, policies, and practices that influence a population’s health perceptions and functional status.
- On the basis of a synthesis of the scientific literature and advice from its public health partners, CDC has defined HRQOL as “an individual’s or group’s perceived physical and mental health over time.”3
The construct of HRQOL enables health agencies to legitimately address broader areas of healthy public policy around a common theme in collaboration with a wider circle of health partners, including social service agencies, community planners, and business groups.7
HRQOL questions have become an important component of public health surveillance and are generally considered valid indicators of unmet needs and intervention outcomes. Self-assessed health status is also a more powerful predictor of mortality and morbidity than many objective measures of health.9-10 HRQOL measures make it possible to demonstrate scientifically the impact of health on quality of life, going well beyond the old paradigm that was limited to what can be seen under a microscope.
Why is it important to track HRQOL?
Focusing on HRQOL as an outcome can bridge boundaries between disciplines and between social, mental, and medical services. Several recent federal policy changes underscore the need for measuring HRQOL to supplement public health’s traditional measures of morbidity and mortality. Healthy People 2000, 2010, and 2020 identified quality of life improvement as a central public health goal.
- HRQOL is related to both self-reported chronic diseases (diabetes, breast cancer, arthritis, and hypertension) and their risk factors (body mass index, physical inactivity, and smoking status).3
- Measuring HRQOL can help determine the burden of preventable disease, injuries, and disabilities, and can provide valuable new insights into the relationships between HRQOL and risk factors.
- Measuring HRQOL will help monitor progress in achieving the nation’s health objectives.
Analysis of HRQOL surveillance data can identify subgroups with relatively poor perceived health and help to guide interventions to improve their situations and avert more serious consequences. Interpretation and publication of these data can help identify needs for health policies and legislation, help to allocate resources based on unmet needs, guide the development of strategic plans, and monitor the effectiveness of broad community interventions.
How can HRQOL be measured?
During the early 1990s, CDC’s Division of Adult and Community Health, Disability Prevention Program, Women’s Health Program, National Center for Health Statistics Questionnaire Development Research Lab, and Epidemiology Program Office worked to develop and validate a compact set of measures that states and communities could use to measure HRQOL.8 These are the Healthy Days measures, an integrated set of broad questions about recent perceived health status and activity limitation. On the basis of a synthesis of the scientific literature and advice from its public health partners, the CDC has defined HRQOL as “an individual’s or group’s perceived physical and mental health over time.”3
Learn more about how CDC measures HRQOL on the Methods and Measures page.
- Preamble to the Constitution of the World Health Organization as adopted by the International Health Conference, New York, 19-22 June, 1946; signed on 22 July 1946 by the representatives of 61 States (Official Records of the World Health Organization, no 2, p. 100) and entered into force on 7 April 1948.
- The WHOQOL Group. The World Health Organization Quality of Life Assessment (WHOQOL). Development and psychometric properties. Soc Sci Med 1998;46:1569-1585.
- Centers for Disease Control and Prevention. Measuring healthy days: Population assessment of health-related quality of life. Centers for Disease Control and Prevention, Atlanta, Georgia 2000.
- Gandek B, Sinclair SJ, Kosinski M, Ware JE Jr. Psychometric evaluation of the SF-36 health survey in Medicare managed care. Health Care Financ Rev 2004;25(4):5-25.
- McHorney CA. Health status assessment methods for adults: past accomplishments and future directions. Annual Rev Public Health 1999; 20:309-35.
- Selim AJ, Rogers W, Fleishman JA, Qian SX, Fincke BG, Rothendler JA, Kazis LE. Updated U.S. population standard for the Veterans RAND 12-item Health Survey (VR-12). Qual Life Res. 2009;18(1):43-52.
- Kindig DA, Booske BC, Remington PL. Mobilizing Action Toward Community Health (MATCH): metrics, incentives, and partnerships for population health. Prev Chronic Dis 2010;7(4). http://www.cdc.gov/pcd/issues/2010/jul/10_0019.htm.
- Hennessy CH, Moriarty DG, Zack MM, Scherr PA, Brackbill R. Measuring health-related quality of life for public health surveillance. Public Health Rep 1994;109(5):665–672.
- Dominick KL, Ahern FM, Gold CH, Heller DA. Relationship of health-related quality of life to health care utilization and mortality among older adults. Aging Clin Exp Res 2002;14(6):499–508.
- DeSalvo KB, Bloser N, Reynolds K, He J, Muntner P. J. Mortality prediction with a single general self-rated health question. A meta-analysis. Gen Intern Med2006;21(3):267-75.