Most older adults prioritize retaining the ability to bathe, dress, walk, and perform household tasks independently as they age. Yet much remains to be understood about the causes of disability among this age group. In a new Yale study, published in JAMA Network Open, researchers examined the differences in active and disabled life expectancy among older people who experience illness and injury.

Active life expectancy is the projected number of years a person will live without disability, and disabled life expectancy is the number of years one will require assistance to perform daily activities. Together, active life expectancy and disabled life expectancy equal total life expectancy.

“Age, cognitive impairment, and physical frailty may make older persons more vulnerable, but these factors don’t lead directly to disability,” says Thomas Gill, MD, Humana Foundation Professor of Medicine (Geriatrics) at Yale School of Medicine (YSM), professor of epidemiology (chronic diseases) at the Yale School of Public Health, and lead author of the study. “In this study, we sought to build on our prior work showing that having an illness or injury that leads to hospitalization has a more pronounced deleterious effect on older persons’ function than being aged 85 as opposed to 75.”

For the study, the researchers used data from the Yale Precipitating Events Project, a unique longitudinal study of community-living older persons that includes monthly assessments of functional status and complete ascertainment of intervening illnesses and injuries for more than 23 years.

The researchers found that, among 754 initially nondisabled persons aged 70 and older, active life expectancy consistently decreased as the number of hospital admissions increased for critical illness, major nonelective surgery, and reasons other than critical illness or major surgery, but not for major elective surgery.

“Maintaining independent function is a highly valued outcome among older adults,” says Lauren Ferrante, MD, MHS, associate professor of medicine (pulmonary, critical care, and sleep medicine) at YSM and co-author of the paper. “This research sheds light on the health events, such as critical illness, that are most consequential for active and disabled life expectancy, which may help clinicians target restorative interventions after hospital discharge.”

The findings suggest that active life expectancy for those over 70 is significantly diminished in the setting of serious illnesses and injuries, the researchers said. Still, there are multiple ways to reduce the likelihood of becoming disabled, according to Gill.

“For example, many of these hospitalizations are preventable,” he says. “Older persons can get vaccinated against flu and other infections, manage chronic conditions through medications, and take steps to prevent falls.”

If hospitalized, there are strategies, such as preventing delirium and mobilizing older patients, that can reduce the likelihood of prolonged hospital stays, Gill adds.

“Older persons don’t want to spend a large proportion of their remaining life disabled,” Gill says. “Fortunately, there are plenty of opportunities to intervene on an individual and a systems level to help these individuals maintain functional independence.”

Other Yale authors of the study include Emma Zang, PhD, Linda Leo-Summers, MPH, Evelyne Gahbauer, MD, MPH, Robert Becher, MD, and Ling Han, MD, PhD.

The research reported in this news article was supported by the National Institute on Aging (award R01AG017560) of the National Institutes of Health (NIH). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. The study was conducted at the Yale Claude D. Pepper Older Americans Independence Center, which is funded by the NIH (award P30AG021342).

Yale Department of Internal Medicine’s Section of Geriatrics strives to improve the health of older adults by providing exceptional patient care, training future leaders and innovators in aging, and engaging in cutting-edge research. To learn more about their mission, visit Geriatrics.