New Haven, Conn. -- In the largest examination to date of the health consequences of ageism, or age-based bias, researchers at the Yale School of Public Health have found evidence that it harms the health of older people in 45 countries and across 5 continents. The study included over 7 million participants.
Yale Professor Becca Levy was asked by the World Health Organization to lead the analysis as part of its newly launched Global Campaign to Combat Ageism, which is supported by 194 countries. Levy is a professor at the Yale School of Public Health and in the Yale Psychology Department.
The analysis was based on a systematic review of 422 studies around the world. 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," said Levy, the study's senior author. The study appears in the current PLOS ONE journal.
The Yale School of Public Health study is the first systematic review of ageism that simultaneously considered structural-level ageism, such as denied access to health care, and individual-level ageism, such as the power of stress-inducing negative age stereotypes assimilated from culture to affect the health of older persons.
The Yale team 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. This survival finding, which was originally identified by Levy in previous research, was later found by the studies of others in multiple countries, including Australia, Germany, and China.
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. Evidence of denied access to health care treatments was found 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, said the researchers.
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," said first author E-Shien Chang, a Ph.D. candidate in the Department of Social and Behavioral Sciences at the Yale School of Public Health. "Policies to improve older persons' health must take ageism into account."
Other members of the research team included Yale School of Public Health Professor Shi-Yi Wang, Sneha Kannoth, Samantha Levy, and John E. Lee.