Chronological age itself plays almost no role in accounting for differences in older people's health and well-being, according to a new, large-scale study by a multidisciplinary team of researchers at the University of Chicago.
The work, part of the National Social Life, Health, and Aging Project (NSHAP), supported by the National Institute on Aging of the National Institutes of Health, is a major longitudinal survey of a representative sample of 3,000 people aged 57 to 85 done by the independent research organization NORC at UChicago. The study yielded comprehensive new data about the experience of aging in America that formed the underpinning of the research and its conclusions.
The research presents a sharp departure from the traditional biomedical model's reliance on a checklist of infirmities centered on heart disease, cancer, diabetes, high blood pressure, and cholesterol levels.
Using what they call a "comprehensive model" of health and aging, the team has shown how other factors such psychological well-being, sensory function, mobility and health behaviors are essential parts of an overall health profile that better predicts mortality.
"The new comprehensive model of health identifies constellations of health completely hidden by the medical model and reclassifies about half of the people seen as healthy as having significant vulnerabilities that affect the chances that they may die or become incapacitated within five years," said UChicago biopsychologist Martha McClintock, lead author of "An Empirical Redefinition of Comprehensive Health and Well-being in the Older Adults of the U.S.," in the current issue of the Proceedings of the National Academy of Sciences.
"At the same time, some people with chronic disease are revealed as having many strengths that lead to their reclassification as quite healthy, with low risks of death and incapacity," co-author and demographer Linda Waite added.
The paper is based on the results of a major longitudinal study of aging Americans, funded by the National Institute on Aging, that is the first of its kind to collect this sort of information from a scientifically selected group of people.
The comprehensive model reflects a definition of health long advanced, but little studied, by the World Health Organization that considers health to include psychological, social, and physical factors in addition to the diseases that are the basis for the current medical model of health.
McClintock is the David Lee Shillinglaw Distinguished Service Professor in Psychology. Waite is the Lucy Flower Professor in Sociology. Other members of the team are geriatrician William Dale, associate professor of medicine, and chief, Section of Geriatrics & Palliative Medicine at UChicago Medicine; and sociologist Edward Laumann, the George Herbert Mead Distinguished Service Professor in Sociology.
In addition to finding that chronological age itself plays little or no role in determining differences in health, the research also found that:
- Cancer by itself is not related to other conditions that undermine health.
- Poor mental health, which afflicts one in eight older adults, undermines health in ways not previously recognized.
- Obesity seems to pose little risk to older adults with excellent physical and mental health.
- Sensory function and social participation play critical roles in sustaining or undermining health.
- Having broken a bone since age 45 is a major marker for future health issues in people's lives.
- Older men and women have different patterns of health and well-being during aging.
- Mobility is one of the best markers of well-being.
Six new ways of looking at aging
The comprehensive model's healthiest category represented 22 percent of older Americans. This group was typified by higher obesity and blood pressure, but had fewer organ system diseases, better mobility, sensory function, and psychological health. They had the lowest prevalence of dying or becoming incapacitated (six percent) five years into the study.
A second category had normal weight, low prevalence of cardiovascular disease and diabetes, but had one minor disease such as thyroid disease, peptic ulcers, or anemia and were twice as likely to have died or become incapacitated within five years. Two emerging vulnerable classes of health traits, completely overlooked by the medical model, included 28 percent of the older population. One group included people who had broken a bone after age 45. A second new class had mental health problems, in addition to poor sleep patterns, engaged in heavy drinking, had a poor sense of smell and walked slowly, all of which correlate with depression.
The most vulnerable older people were in two classes, one characterized by immobility and uncontrolled diabetes and hypertension. A majority of people in each of these categories were women, who tend to outlive men.
"From a health system perspective, a shift of attention is needed from disease-focused management, such as medications for hypertension or high cholesterol, to overall well-being across many areas," said Dale.
"Instead of policies focused on reducing obesity as a much lamented health condition, greater support for reducing loneliness among isolated older adults or restoring sensory functions would be more effective in enhancing health and well-being in the older population," said Laumann.