If the prevalence of disabilities had remained at 2008 levels, an additional 1.27 million older Americans would have had difficulties bathing or dressing and an additional 1.89 million would have serious difficulty walking or climbing stairs by 2017

The prevalence of disabilities among American adults aged 65 and older is much lower than it was for the same age group a decade earlier, according to a nationally representative study published online in the International Journal of Environmental Research and Public Health (IJERPH) .

The decline in disability among older Americans was substantial. The odds of experiencing limitations in activities of daily living (such as dressing or bathing) and the odds of experiencing functional limitations (such as serious difficulty walking or climbing stairs) declining 18% and 13%, respectively, between 2008 and 2017.

In 2008, 12.1% of older Americans reported limitations in activities of daily living. In 2017, this percentage had declined to 9.6%. To put this into perspective, if the prevalence of limitations in daily living remained at the 2008 levels, an additional 1.27 million older Americans would have ADL limitations in 2017.

Similarly, the percentage of functional limitations among those 65 and older declined from 27.3% in 2008 to 23.5% in 2017. As a result, 1.89 million fewer older adults experienced functional limitations on their quality of life.

"The dramatic improvement in the prevalence of older Americans experiencing disabilities has important implications for our communities," says first author Esme Fuller-Thomson, director of the University of Toronto's Institute for Life Course & Aging and professor at the Factor-Inwentash Faculty of Social Work (FIFSW) and the Department of Family & Community Medicine. "This decline in the prevalence of disabilities has a wide range of benefits for older adults, their families and caregivers, and the health care system at large."

The improvements in disabilities among older adults was greater for women than for men.  After adjusting for age and race, women's odds of experiencing limitations in activities of daily living decreased by 20%. vs 13% for men. The odds of women experiencing functional limitations decreased 16% compared to only an 8% decrease among men.

"While it is unclear why these gender differences exist, previous research suggest that women are more likely than men to have annual check-ups and adopt preventative care practices, and this may contribute to this gender gap," says co-author Jason Ferreirinha a recent Master of Social Work graduate from University of Toronto's FIFSW.

Further analyses showed a relationship between some of the observed improvements in disabilities across the decade and the proportion of high school and university graduates among the post-World War II birth cohorts.

"Higher educational attainment increases health literacy and health promoting behaviours," says co-author Katherine Ahlin, a recent graduate from the MSW program at the University of Toronto's FIFSW. "One's education levels also impact job type, which affects cardiovascular risk factors. And the lower one's cardiovascular risk factors, the lower one's levels of disability later in life."

Other factors may be at play that warrant future research say the researchers. "Other possible contributors to this positive trend could include decreases in smoking, decreasing levels of air pollutants and the phase out of leaded gasoline in the 1970s," says Fuller-Thomson.

The study is based on an analysis of 10 consecutive cross-sectional waves of the American Community Survey (2008-2017), a nationally representative cross-sectional survey of both community dwelling and institutionalized older adults.  Approximately half a million older adults were included in each year of data collection, resulting in a final sample size of 5.4 million American respondents aged 65 and older.

Interestingly, the study found a more modest decline in disability among those in the Baby Boomer generation compared to older cohorts. The authors suggested that higher rates in obesity among Baby Boomers compared to their older counterparts may be playing a role in a slower decline.

"Our findings from this study indicate a steep decline in the prevalence of disability among older Americans," said Ferreirinha. "Further investigation will be needed to explore if these positive trends will continue in coming decades as the Baby Boom population ages into their 80s."