Doctors and dentists are still prescribing large quantities of opioids, despite government guidelines urging doctors to avoid prescribing the drugs or to minimize their use whenever possible, according to an investigation by NPR.

Health care providers are writing enough opioid prescriptions each year for half of all Americans to have one, according to NPR’s analysis of public data. Doctors continue to regularly prescribe opioids even for relatively mild pain conditions, such as lower back pain and muscle strain.

“We’re 5% of the world’s population, but we consume 80% of the world’s prescription opioids,” said Dr. Jonathan Chen, a physician and researcher at Stanford University Medical Center who studies prescribing patterns. “It’s not just a handful of doctors doing it. We kind of all are. It’s become part of our culture that this is normal.”