On April 7, 2019, the World Health Organization (WHO) turned 71—surpassing the proverbial life span of “three score and ten.” Its definition of health as a “state of complete physical, mental and social well-being and not merely the absence of disease or infirmity” has been a guiding framework for the Centers for Disease Control and Prevention (CDC), Pan American Health Organization, and other WHO partners.1(p43) This circa-1948 definition reflected postwar optimism for the control of communicable diseases and the promise of the world’s children. Since then, communicable diseases such as smallpox, polio, diphtheria, and tetanus have been brought under control, infant and childhood mortality have fallen, and life expectancies worldwide have dramatically risen.
Longer lives foreground a new health concern: living well with multiple chronic conditions. Chronic diseases are prevalent, nearly ubiquitous, in older adults. More than two thirds of Americans aged 65 years and older are managing two or more diseases; one in seven is managing six or more diseases.2 Globally, noncommunicable diseases now account for 73% of deaths and a wide spectrum of disabilities.3 The WHO definition of “complete” health thereby sets either unrealistic expectations for older adults or categorically excludes them from frameworks of health. Do we need a new definition of health to incorporate aging populations into its basic tenets? What measures will advance attention to the health needs of this growing, at times vulnerable, and largely overlooked population?
Context matters. Important changes in population aging and disease management in the last 70 years urge new consideration of the particular health needs of the elderly as an essential component of health in an aging world.
WHO FRAMEWORK FOR HEALTH, 1946–1948
In the summer of 1946 in New York City, the United Nations (UN) convened the International Health Conference, which led to the creation of the WHO in 1948.4 Sixty-one nations, including the United States and members of the UN, signed its Constitution. The chair of the US delegation, Surgeon General Thomas Parran, commended the WHO Constitution as a “magna carta for health,” guiding postwar efforts for eradicating disease, fostering international peace, and ensuring the health of the world’s children.1(piii) The organization set out as its first objective the meaning of health as complete physical, mental, and social well-being. It also emphasized the health of the world’s youths: “the heathy development of the child is of basic importance,” the Constitution stated in its sixth objective, adding that living “harmoniously in a changing total environment” was essential to children’s healthy development.1(p43) Although life expectancies in much of the developed world were already approaching 70 years, no similar provision for the health of the elderly was included, nor has one since been added.
CHANGING CONTEXTS OF DISEASE
In the years between the definition’s adoption and today, global life expectancy has risen from approximately 48 to 71 years for men and 53 to 76 years for women. Mortality of children younger than five years has declined sharply, while the population of adults aged 65 years and older has grown numerically and proportionally—from 131 million people representing 5% of the global population in 1950 to 617 million people constituting nearly 9% of the world’s population in 2015.2
Changing definitions of disease have accompanied rising life expectancies, challenging concepts of health that rely on the absence of disease. Hypertension, for example, is one of the most common chronic conditions in older adults and a central risk factor for the top two causes of death worldwide in 2016—heart disease and stroke. The definition of hypertension, however, has changed. Thresholds for treatable hypertension have been repeatedly lowered, from a systolic pressure of greater than 180 and a diastolic pressure of greater than 110 millimeters of mercury and evidently ill in the 1940s, to a systolic pressure of greater than 130 and a diastolic pressure of greater than 80 millimeters of mercury and often asymptomatic in 2017.5 Improved management of hypertension has helped reduce age-adjusted mortality rates from heart disease and stroke while also extending the management of disease across longer segments of the life course.
Changes in screening, diagnosis, and treatment have affected the lifetime management of numerous other conditions from cancer to HIV/AIDS. The treatment of malignant tumors, the second leading cause of death in 1948 and 2016, has been transformed by routine screenings, early detection, and novel therapeutics. For many patients, cancer is a chronic disease. Under the terms of the WHO definition, are these individuals who live in a state of elevated risk and more vigilant screening healthy or diseased? Changing definitions of disease have altered their prevalence while new treatments affect morbidity, such that many other diseases can last for decades and produce few or no symptoms if managed well. We need new definitions of health to reflect these new experiences of disease management and their prevalence in later life.
INCREASING ATTENTION TO AGING ADULT HEALTH
A 2011 conference in the Netherlands suggested the “ability to adapt and self-manage” as a new guideline for defining health, although there has been little, if any, response to these efforts.6 Indeed, amending the WHO Constitution would likely involve an extensive process of debate, which may not ultimately result in adoption and may introduce unpredictable risks and outcomes. Revising the definition may also reactivate previous debates over components of health (such as spirituality) or the extent of WHO governance over the private sector.
Another strategy to increase attention to elderly persons and guide interpretations of health is through international human rights instruments. Recently, scholars across fields have advocated rights-based approaches to health, including calling for WHO leadership to prioritize the Framework Convention on Global Health, a proposed global health treaty grounded in the right to health.7 International human rights documents, from the Universal Declaration of Human Rights to the International Covenant on Economic, Social, and Cultural Rights have included provisions for maternal and child health, migrants, and other special populations, but have given limited attention to old age.
In 2000, the UN Committee on Economic, Social, and Cultural Rights adopted a General Comment No. 14 on the Right to Health, which described combining elements of preventive, curative, and rehabilitative health care for older persons. Aging populations merit further attention, and preparing a new General Comment on Health, for example, could emphasize the optimal management of disease, importance of continuous access to care, and need for rebalancing health risks and priorities in later life. It could also describe the particular hurdles facing elderly persons as physical and cognitive health evolves, including vulnerability to disease, poverty, abuse, stigma, and challenges to autonomy, alongside considerations of end-of-life care.
Other guiding documents and programs could acknowledge changing meanings of health for aging populations. The WHO and CDC healthy aging initiatives could reflect on the tensions between “complete” health and the importance of early and excellent disease management, while UN Sustainable Development Goals and US Healthy People frameworks could work to bridge the gap between healthy aging ideals, disease management, and end-of-life care. National constitutions may also promote access to health services, social participation and inclusion, and other determinants of health in older populations.
Aging populations present important challenges to definitions of health established a lifetime ago, but they also provide an opportunity to reflect on new directions for and critical components of health. As the world faces life expectancies rising beyond 65 years, we urge acknowledgment that many lives are lived with disease, that with proper resources these diseases can be reasonably managed, and that living with and managing diseases in old age should be recognized as a central component of lifelong well-being. People of all ages deserve the opportunity to be healthy.
ACKNOWLEDGMENTS
We would like to thank David S. Jones, Steven Joffe, and our anonymous reviewers for their generous insights and feedback on the article.
CONFLICTS OF INTEREST
J. Karlawish is an investigator in a clinical trial sponsored by Novartis and a clinical trial sponsored by Lily Inc. In the last 12 months, he was a consultant to Squintmetrics Inc, paid less than $5000.
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