As the world's population of older adults increases, so do conversations around successful aging -- including seniors' physical, mental and social well-being.
A variety of factors can impact aging adults' quality of life. Two big ones, according to new research from the University of Arizona, are the health and cognitive functioning of a person's spouse.
Analyzing data from more than 8,000 married couples -- with an average age in the early 60s -- researchers found that the physical health and cognitive functioning of a person's spouse can significantly affect a person's own quality of life.
The findings have implications for how to most effectively address quality-of-life issues in people's later years.
"When we think about quality of life for older adults, and improving quality of life, it seems like targeting the individual is only part of the story, and our findings suggests that for older adults, a larger part of individual well-being is defined by our partner's health and cognitive functioning as well," said UA psychologist David Sbarra, a co-author of the paper, which will be published in Psychology and Aging, a journal of the American Psychological Association.
The population of Americans age 65 years or older is expected to double during the next 25 years to about 72 million, as baby boomers age and people live longer. By 2030, older adults will account for roughly 20 percent of the U.S. population and health-care spending will increase by 25 percent, largely because of the aging population, according to the Centers for Disease Control and Prevention.
"As we build public health interventions for our aging population when it comes to quality of life, we need to take a more dyadic approach, looking at both partners," said Sbarra, an associate professor in the UA Department of Psychology with joint appointments in Family Studies and Human Development (link sends e-mail) and the Evelyn F McKnight Brain Institute.
The study was based on analysis of data from the Survey of Health, Aging and Retirement in Europe, or SHARE study, of adults age 50 and older. The data was collected at three intervals over a six-year period, between 2004-2005 and 2010-2011.
UA researchers considered survey respondents' self-reports of physical health and quality of life, as well as their scores on cognition tests measuring verbal fluency, word recall and delayed word recall. The UA study looked at health and cognition across a normal spectrum, rather than focusing on clinical cognitive disorders or chronic illnesses.
The findings support existing research on the interdependence of older married couples, and they extend that research by identifying cognition and physical health as two specifically important factors that influence spouses' quality of life.
Kyle Bourassa, a UA doctoral student in clinical psychology and the paper's lead author, said husbands' and wives' quality of life appears to be equally impacted by their spouse's physical health, with no differences across gender lines. In other words, a wife's physical health impacts her husband's quality of life as much as a husband's physical health affects his wife's quality of life.
"If you have people whose physical health is low -- maybe they're suffering from an illness or unable to walk -- those kind of physical health issues not only impact the individual but the person they're married to as well," Bourassa said. "Their husband or wife is the one who may have to adjust and help with their partner's new lifestyle."
With regard to cognition, wives' cognitive functioning appears to have as much of an effect of husbands' quality of life as husbands' own cognitive abilities. Wives' quality of life was not as strongly affected by their husbands' cognition, but there was a measurable impact, Bourassa said.
Finally, changes in participants' self-reported overall quality of life at the three intervals in the SHARE survey varied similarly between husbands and wives, suggesting that change in one spouse's life quality over time parallels change in the other's.
As adults age, changes in physical health can be a natural part of the process, as can cognitive decline, which can range from normal change in cognition to the onset of disorders such as dementia or Alzheimer's disease. As this change can vary dramatically between different people, it makes sense to look at both physical health and cognition as they relate to quality of life for both partners, Bourassa said. Additional research is needed to determine how changes in these two areas can change quality of life over time, he said.
"The population of aging adults is going up drastically, and as we have more and more people who are living longer and longer it's really important to understand successful aging," said Bourassa, whose co-authors on the paper included Sbarra and UA psychology doctoral students Molly Memel and Cindy Woolverton.
Said Bourassa: "You could extend these findings to think about interventions targeting cognition and physical health to improve quality of life not only for the individual, but also for their partner."