Seven researchers contributed to the analysis, which was published in the Journal of the American Medical Association. The contributors crunched the numbers recorded by the National Vital Statistics System Mortality file, a storehouse of death data from all 50 states and the District of Columbia, from between 2000 to 2015.
It found that the average American life expectancy grew overall from 2000 to 2015, but that the astounding rise in opioid-related deaths shaved 2.5 months off this improvement.
That’s .21 years, compared to the .02 years taken off the average life expectancy by alcohol overdoses.
No factor negatively affected life expectancy more.
“It really underlines how serious the problem of opioid overdose has become in the U.S.,” Deborah Dowell, senior medical adviser in the division of unintentional injury prevention at CDC, told Time. “In general we don’t see decreases in life expectancy attributable to a single cause that are of this magnitude.”
While overdose deaths in general in the U.S. more than doubled in that 15-year span, opioid overdoses more than tripled, the study reported.
The average life expectancy for an American born in 2010 was 76.8 years, which grew to 78.8 years in 2015. The study suggested that but for opioid-related deaths, it would have been higher still.
Opioid overdose still hasn’t cracked the top 12 leading causes of death — which, aside from suicide and unintentional injuries, are all medical conditions — but it’s close.
The 12th leading cause of death in 2015 was chronic liver disease and cirrhosis, which killed 40,326 people. Opioid overdoses, meanwhile, claimed 33,091 lives that same year.
The gap was much wider in 2000, when liver disease killed 26,552 Americans while opioid overdoses killed 8,407.
“These findings suggest that preventing opioid-related poisoning deaths will be important to achieving more robust increases in life expectancy once again,” the researchers concluded.