Arguably the greatest American advancement of the 20th century was the 30-year increase in U.S. life expectancy at birth, from 47 years in 1900 to 77 years in 2000. Having achieved that, it's easy now to take it for granted. Some worrisome signs, though, point to the need to focus on life expectancy once again - locally and nationally.
That focus is important because life expectancy at birth is a vital measure about Americans' lives. It serves, as the World Health Organization notes, as a summary indicator of age at death and, by proxy, of our health.
The first sign should get our attention. Life expectancy in the U.S. fell in 2015, the last year for which complete data are available. While the drop was small - from 78.9 years in 2014 to 78.8 in 2015 - it was the first decline since 1993 and a shift from the positive trajectory that we've been enjoying. While this small decline is hard to interpret, potential culprits include the nation's epidemic of chronic diseases and obesity, as well as the opioid epidemic and the health of our youth.
Another warning sign is the significant disparity in life expectancy across geographic areas. A recent analysis of life expectancy by county in the U.S. shows that geographic disparities are "large and increasing" and that an enormous 20-year gap exists between the counties with the highest (87 years) and lowest (67 years) life expectancies. Several counties in South and North Dakota, especially those with Native American reservations, had the lowest life expectancies, while counties in central Colorado had the highest.
On top of that comes research in The Lancet highlighting that "The life expectancy of the wealthiest Americans now exceeds that of the poorest by 10 to 15 years." A 2016 JAMA study revealed that among the 10 states with the lowest life expectancy, eight formed a geographic belt: Michigan, Ohio, Indiana, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas.
That study also examined life expectancy in four cities: New York, San Francisco, Dallas, and Detroit. Among low-income individuals, there was substantial variation in life expectancy across these cities, but little variation among high-income individuals. The researchers concluded that "low-income individuals tend to live longest (and have more healthful behaviors and have greater health) in affluent cities with highly educated populations and high levels of government expenditures."
These extraordinary disparities by geography and income are evident even with the Affordable Care Act and its increased access to care by poorer Americans. Only time will tell what changes in access - and in life expectancy - will occur under the revisions now being pursued by the federal government.
A third sign of concern is America's standing compared to other countries. In 2015, life expectancy at birth in the U.S. was nearly 79 years, compared to 81 in the European Union. More than 30 nations have life expectancies exceeding ours, including Hong Kong and Japan (the highest at 84 each), as well as France, Iceland, Italy, Singapore, Spain, Sweden, and Switzerland (at 83 each). Even Cuba, with many fewer resources for health care than in the U.S., beats us (at 80). The poorest men in America have life expectancies similar to men in Honduras and Paraguay.
These patterns and disparities in U.S. life expectancy should be a clear call to action for us. We can certainly do better than to have a 20-year difference in length of life by county, and to trail other countries in life expectancy at birth.
The United States has the data to attack the problem strategically and the public health expertise needed to analyze the data, propose strategies to raise life expectancy, and help create conditions that improve health and longevity for all. It's now time to fund our public health experts and systems to improve health and life expectancy across the nation.
Linda P. Fried, M.D., is dean of the Columbia University Mailman School of Public Health.