Ageism can harm older people’s health, a review of research in 45 countries across 5 continents shows.

The researchers base their analysis on a systematic review of 422 studies around the world that included over 7 million participants. There was evidence of the adverse effects of ageism on older persons in 96% of the studies.

“The injurious reach of ageism that our team documented demonstrates the need for initiatives to overcome ageism,” says senior author Becca Levy, a professor at the School of Public Health and the psychology department at Yale University. The World Health Organization asked Levy to lead the analysis as part of its newly launched Global Campaign to Combat Ageism, which 194 countries support.

The study is the first systematic review of ageism that simultaneously considered structural-level bias, such as denied access to health care, and individual-level bias, such as the power of stress-inducing negative age stereotypes assimilated from culture to affect the health of older persons.

The researchers found evidence that ageism led to worse outcomes in a number of mental health conditions, including depression, and a number of physical health conditions, including shorter life expectancy.

Ten studies showed that when older persons assimilate negative age stereotypes from the culture, they have a shorter life expectancy. Studies in multiple countries including Australia, Germany, and China made this survival finding, which Levy originally identified in previous research.

In the current study, Levy and her team found that ageism adversely affected whether or not older patients received medical treatment and, if they received the treatment, the duration, frequency, and appropriateness of the treatment provided. Researchers found evidence of denied access to health care treatments in 85% of all relevant studies. In 92% of the international studies of health care students and professionals, there were indications of ageism in medical decisions, and this trend has increased over time, the researchers say.

This systematic review also found ageism affected older persons regardless of their age, sex, and racial/ethnic membership.

“Our research highlights the importance of recognizing the influence of ageism on health,” says first author E-Shien Chang, a PhD candidate in the social and behavioral sciences department at the Yale School of Public Health. “Policies to improve older persons’ health must take ageism into account.”

The study appears in PLOS ONE.

Source: Yale University

Original Study DOI: 10.1371/journal.pone.0220857