The deadly drug overdose epidemic that has been ravaging the nation may be even worse than we realize.

A new University of Virginia study says the numbers of deaths due to heroin and opioid overdoses have actually been severely underreported.

Dr. Christopher Ruhm revisited thousands of death certificates from 2008 through 2014 and concluded the mortality rates were 24 percent higher for opioids and 22 percent higher for heroin than had been previously reported.

“Opioid mortality rate changes were considerably understated in Pennsylvania, Indiana, New Jersey and Arizona,” the study states. “Increases in heroin death rates were understated in most states, and by large amounts in Pennsylvania, Indiana, New Jersey, Louisiana and Alabama.”