Life expectancy of a significant segment of the U.S. population is declining or at best stagnating

Apr 21 2008

One of the major aims of the U.S. health system is improving the health of all people, particularly those segments of the population at greater risk of health disparities. In fact, overall life expectancy in the U.S. increased more than seven years for men and more than six years for women between 1960 and 2000.

Now, a new, long-term study of mortality trends in U.S. counties over the same four decades reports a troubling finding: These gains are not reaching many parts of the country; rather, the life expectancy of a significant segment of the population is declining or at best stagnating.

Researchers at the Harvard School of Public Health (HSPH) and the University of Washington found that 4% of the male population and 19% of the female population experienced either decline or stagnation in mortality beginning in the 1980s.

“There has always been a view in U.S. health policy that inequalities are more tolerable as long as everyone’s health is improving. There is now evidence that there are large parts of the population in the United States whose health has been getting worse for about two decades,” said Majid Ezzati, Associate Professor of International Health at HSPH and lead author of the study.

The majority of the counties that had the worst downward swings in life expectancy were in the Deep South, along the Mississippi River, and in Appalachia, extending into the southern portion of the Midwest and into Texas.

The researchers analyzed mortality data from the National Center for Health Statistics and population data from the U.S. Census Bureau between 1959 and 2001. The study is the first to look at mortality trends in the U.S. by county over such a long period of time. (County data is the smallest measurable unit for which mortality data is available.) The National Center for Health Statistics stopped providing data after 2001.

The results showed that, between 1961 and 1999, average life expectancy in the U.S. increased from 66.9 to 74.1 years for men and from 73.5 to 79.6 for women. Looking at individual counties, however, the researchers found that beginning in the 1980s, the best-off counties continued to improve but there was a stagnation or worsening of life expectancy in the worst-off counties--what the researchers refer to as “the reversal of fortunes.” As a result, while men in the best-off counties lived 9.0 years longer than those in the worst-off counties in 1983, by 1999 that gap had increased to 11.0 years; for women the 1983 life expectancy gap of 6.7 years increased to 7.5 years by 1999. Over the past few decades, life expectancy in high-income countries around the world has gradually risen, with few exceptions.

Given the consistent trend of declining mortality rates in high-income countries, the results of this study, which show large segments of the American population experiencing stagnating or worsening health conditions, are particularly troubling. Ezzati said, “The finding that 4% of the male population and 19% of the female population experienced either decline or stagnation in mortality is a major public health concern.” Christopher Murray, Director of the Institute for Health Metrics and Evaluation at the University of Washington and co-author of the study, added that “life expectancy decline is something that has traditionally been considered a sign that the health and social systems have failed, as has been the case in parts of Africa and Eastern Europe. The fact that is happening to a large number of Americans should be a sign that the U.S. health system needs serious rethinking.”

The researchers also analyzed data on deaths from different diseases and showed that the stagnation and worsening mortality was primarily a result of an increase in diabetes, cancers and chronic obstructive pulmonary disease, combined with a slowdown or halt in improvements in cardiovascular mortality. An increase in HIV/AIDS and homicides also played a role for men, but not for women.

The diseases that are responsible for this troubling trend seem to be most related to smoking, high blood pressure, and obesity. “Smoking and blood pressure have a long history of being controlled through both personal and population strategies. There is good evidence on relatively low-cost and effective ways of dealing with these issues if one of the health system’s imperatives becomes to close this widening life expectancy gap,” said Ezzati.

The study appears in the April 22, 2008, edition of the open-access journal PLoS Medicine.