Recent research conducted by Princeton economists Angus Deaton and Anne Case has found that the death rate of white, middle-aged Americans has been on a fast rise and has almost matched the deaths that have resulted from the spread of acquired immune deficiency syndrome (AIDS), according to The Guardian.
In particular, the trend is most prevalent among 45 to 54-year-olds with no more than a high school education, something that is not seen in any other age group in the U.S.
"This was absolutely a surprise to us. It knocked us off our chairs," said Case. "We wanted to make sure we weren't missing something. Everyone's been stunned."
The research showed that the mortality rate for white, undereducated Americans between 45 and 50 years old has increased by 134 deaths per 100,000 people from the time period of 1999 to 2014, according to The New York Times.
"It is difficult to find modern settings with survival losses of this magnitude," wrote Ellen Meara and Jonathan S. Skinner in a commentary on the findings.
Although more research needs to be conducted to pinpoint the exact causes, the researchers believe that it could be linked to higher suicide rates, higher financial stresses, misuse of drugs and alcohol, cheaper high-quality heroin and easier access to prescription painkillers.
The findings come after decades that saw mortality rates declining due to advancements in the medical and healthcare industries, according to The Wall Street Journal.
