To see how the United States measures up in terms of life expectancy, researchers at the Centers for Disease Control and Prevention compared its death rates in 2012 with those of a dozen other countries with similar economies, including the United Kingdom, Japan, Germany and other European countries.
The researchers found that men and women in the United States lived 2.2 fewer years than residents in similar countries. American men and women could only look forward to a life expectancy of 76.4 and 81.2 years, respectively, compared with the 78.6 and 83.4 years of their peers abroad.
"The idea that Americans live several years shorter than we would expect them to, given the level of development, is sort of already known, but every time I come across that number it seems staggering that we get two fewer years of life just for living here," said Andrew Fenelon, a senior service fellow at the CDC's National Center for Health Statistics and senior author of the study, which was published on Tuesday in the Journal of the American Medical Association
The current study didn't look at which U.S. age groups were at the greatest disadvantage in terms of life expectancy, "but from my experience the largest gaps are between 25 and 65, so this prime middle-age adulthood," Fenelon said. However, other age groups in the United States, including infants
, have also been known to face higher death rates, he added.
Fenelon and his colleagues took their investigation one step further and asked what is killing Americans. They focused on injuries, which are the leading cause of death for Americans between 1 and 44 years of age. Among injuries, those that are responsible for the greatest number of deaths are drug poisonings, gun injuries and motor vehicle crashes.
They found that these three causes of death were responsible for 48% of the gap in men's life expectancy between the United States and similar countries, and took about a year off their lives in the United States. For women, they accounted for 19% of the discrepancy, costing them about half a year of life.
"I was really surprised at just how large the contribution is" of these three causes of death, Fenelon said.
Many of the drug-poisoning deaths, Fenelon suspects, likely involve prescription opioid abuse and heroin use. These deaths are probably largely accidental, although some may be due to people taking their own lives, he added. The deaths due to firearm-related injuries are probably mostly suicides, and also some homicides, whereas motor vehicle crashes are probably overwhelmingly accidental, Fenelon said.
An earlier study found that death rates among middle-aged white Americans, unlike other age groups, have been on the rise since 1999
, largely because of increases in rates of drug and alcohol abuse and suicide. The current findings support the idea that these types of injuries are major causes of death, and they have probably all been on the rise in recent decades, Fenelon said.
Ellen Meara, associate professor of health policy and clinical practice at the Dartmouth Institute for Health Policy and Clinical Practice, said that the new study agrees with what we already know -- there is a big discrepancy in life expectancy in the United States. "But it's an important point that's worth restating from time to time," she said.
"Our rates of drug poisoning and all of these external causes (of death) are so much more than other countries," Meara said.
However, this has not always been the case. "If you go back far enough in the 1980s, we compared much more favorably in life expectancy with other countries, and gradually over time they improved more than the U.S.," Meara said. "We have to look to see what we are doing or have been doing differently since the 1980s -- it's not like we can't achieve what other countries have."
It could also bear looking at what the United States is doing differently in terms of addressing other causes of death as well. The remainder of the life expectancy gap is probably due to a combination of causes, including higher infant mortality rates here and higher rates of deaths related to smoking, Fenelon said.
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