Study leader Michael Von Korff, a senior investigator at Group Health Research Institute, studied nearly 10,000 patients who received multiple opioid prescriptions for common chronic pain conditions like back pain and osteoarthritis.
Patients who received higher opioid doses were nine times more likely to overdose than were those receiving low doses. Still, most of the overdoses occurred among patients receiving low-to-medium doses, because prescriptions at those levels were much more common, Von Korff said.
"Some studies have indicated that fatal opioid overdoses occur most often among people abusing prescription drugs or obtaining them from non-medical sources," Von Korff said in a statement. "But our results suggest that many overdoses may occur among people using prescribed opioids."
Von Korff said the data reviewed cannot determine whether higher doses are a cause of overdose but he noted physicians should carefully evaluate and closely monitor patients using opioids long-term.
The finding was published in the Annals of Internal Medicine.