Global Health and Aging
Longer Lives and Disability
Are we living healthier as well as longer lives, or are our additional years spent in poor health? There is considerable debate about this question among researchers, and the answers have broad implications for the growing number of older people around the world. One way to examine the question is to look at changes in rates of disability, one measure of health and function. Some researchers think there will be a decrease in the prevalence of disability as life expectancy increases, termed a “compression of morbidity.” Others see an “expansion of morbidity”—an increase in the prevalence of disability as life expectancy increases. Yet others argue that, as advances in medicine slow the progression from chronic disease to disability, severe disability will lessen, but milder chronic diseases will increase. In the United States, between 1982 and 2001 severe disability fell about 25 percent among those aged 65 or older even as life expectancy increased. This very positive trend suggests that we can affect not only how long we live, but also how well we can function with advancing age. Unfortunately, this trend may not continue in part because of rising obesity among those now entering older ages. We have less information about disability in middle- and lower-income countries. With the rapid growth of older populations throughout the world—and the high costs of managing people with disabilities—continuing and better assessment of trends in disability in different countries will help researchers discover more about why there are such differences across countries.
Some new international, longitudinal research designed to compare health across countries promises to provide new insights, moving forward. A 2006 analysis sponsored by the U.S. National Institute on Aging (NIA), part of the U.S. National Institutes of Health, found surprising health differences, for example, between non-Hispanic whites aged 55 to 64 in the United States and England. In general, people in higher socioeconomic levels have better health, but the study found that older adults in the United States were less healthy than their British counterparts at all socioeconomic levels. The health differences among these “young” older people were much greater than the gaps in life expectancy between the two countries. Because the analysis was limited to non- Hispanic whites, the differences did not reflect the generally lower health status of blacks or Latinos. The analysis also found that differences in education and behavioral risk factors (such as smoking, obesity, and alcohol use) explained few of the health differences.
This analysis subsequently included comparable NIA-funded surveys in 10 other European countries and was expanded to adults aged 50 to 74. The findings were similar: American adults reported worse health than did European adults as indicated by the presence of chronic diseases and by measures of disability (Figure 8). At all levels of wealth, Americans were less healthy than their European counterparts. Analyses of the same data sources also showed that cognitive functioning declined further between ages 55 and 65 in countries where workers left the labor force at early ages, suggesting that engagement in work might help preserve cognitive functioning. Subsequent analyses of these and other studies should shed more light on these national differences and similarities and should help guide policies to address the problems identified.
Figure 8. Prevalence of Chronic Disease and Disability among Men and Women Aged 50-74 Years in the United States, England, and Europe: 2004
Source: Adapted from Avendano M, Glymour MM, Banks J, Mackenbach JP. Health disadvan- tage in US adults aged 50 to 74 years: A comparison of the health of rich and poor Americans with that of Europeans. American Journal of Public Health 2009; 99/3:540-548, using data from the Health and Retirement Study, the English Longitudinal Study of Ageing, and the Survey of Health, Ageing and Retirement in Europe. Please see original source for additional information.
Publication Date: October 2011
Page Last Updated: January 22, 2015