Death rates for white Americans ages 45 to 54 climbed half a percent each year between 1999 and 2013, researchers at Princeton University found using mortality data from the Centers for Disease Control and Prevention. In the previous two decades, the death rate for this group had dropped by 2% each year. Middle-aged blacks and Hispanics continued to see a 2% annual decline between 1999 and 2013.
"We have come to expect mortality rates in middle age to continue to decline, which they did throughout most of the 20th century...it was really a surprise to see a sustained period when mortality rates actually increased (among middle-aged white Americans)," said Anne Case, professor of economics and public affairs at Princeton University.
Deaths related to drugs, alcohol, suicide and liver disease are the cause of the increase, researchers said.
Case and her husband, Angus Deaton, a professor at Princeton and winner of the 2015 Nobel Prize in economic science, are co-authors of the study
, which was published Monday in Proceedings of the National Academy of Sciences.
The only other time that death rates increased among middle-aged whites in the last century was in the 1960s because of smoking-related diseases, Case said. There was also a spike in mortality among younger adults in the 1980s during the AIDS epidemic, she said.
What's changing the mortality rate
The recent uptick in mortality among middle-aged whites is largely attributed to deaths from drug and alcohol poisoning, suicide and liver disease. In contrast, the rates of drug overdose and liver disease among black Americans dropped between 1999 and and 2013.
Although the CDC has reported on trends in recent years, such as white people being at higher risk of suicide
and of death from opioid and prescription painkiller overdose
, no study had yet put these trends together to see the impact they had on death rate, Case said.
These causes of death -- drug and alcohol overdose, suicide, liver disease -- also are increasing among whites ages 35 to 44 and ages 55 to 64. Although these increases have not been large enough to drive up mortality in these groups, they have been linked to a leveling off of their death rates, Case said.
Case and Deaton found that the death rate for the more senior group of white people, those age 65 to 74, had continued to decline by about 2% each year between 1999 and 2013, which is comparable to the rates among senior black and Hispanic people.
When the researchers took a closer look at the death rate among middle-aged whites, they found that those with only a high school education or less saw a much larger rise in death rate than those who went to college.
The death rate for middle-aged whites with only a high school education or less increased by 134 per 100,000 between 1999 and 2013. Those with a bachelor's degree or more education saw death rates fall by 57 per 100,000 in that time period. These rates were similar among both men and women, the researchers noted.
What might explain the change in death rate among middle-aged whites is this, Case said: Fewer economic opportunities, especially for those with less education, have led to more despair and worse health, and in turn more abuse of drugs and alcohol.
"We have a lot more work to do to pin down how much of this has to do with not having as many economic resources with just a high school degree," and how much of it is due to other factors, such as less secure pension plans, Case said.
'This epidemic of hopelessness'
This study also raises questions about why black and Hispanics did not see an increase in deaths over this period when they were hit with even more economic challenges than whites, said Ellen Meara, associate professor of healthy policy and clinical practice at the Dartmouth Institute. Meara, who wrote an editorial about the article for the Proceedings of the National Academy of Sciences, called the effect on death rate among middle-aged white Americans "stunning."
"It is almost like there is this epidemic of hopelessness that needs to be understood," and it seems to affect whites more than blacks and Hispanics, Meara said.
Another "puzzle" of this study, Meara said, is why the rise in death rate was not seen in other rich countries.
Mortality among the middle-aged population plummeted in the six other countries that the researchers examined: Australia, Canada, France, Germany, the United Kingdom and Sweden. Although these countries also had economic problems in recent years, its residents might have been less affected because they have more social safety nets in terms of unemployment benefits and health care, Case said.
It is also striking that the causes of death that are driving up mortality among middle-aged white Americans are accidental or intentional harm, rather than obesity-related diseases or cancer, Meara said.
"There is something going on that is not purely biological," she said.