A new study finds 90 percent of people who overdose on prescription opioids continue to receive prescriptions for the drugs.

“We found the results both surprising and concerning,” lead author Dr. Marc R. Larochelle of Boston Medical Center told Reuters. “Stopping opioids alone is not a solution,” he said. “In addition to treatment of any potential opioid use disorder, we need to communicate alternative options for treatment of chronic pain, and all modalities should be considered, including non-opioid medications, physical therapy, and complementary and alternative treatments.”

The researchers analyzed data from a national commercial insurance claims database. They identified almost 3,000 patients who were taking long-term opioids for chronic pain not related to cancer, who experienced a nonfatal overdose between 2002 and 2012.

More than half of the 90 percent of patients who continued to receive opioid prescriptions after their overdose got them from the same doctor, the researchers report in the Annals of Internal Medicine.

Seven percent of patients who overdosed had a second overdose, the study found. Two years after the first overdose, patients who still had an opioid prescription were twice as likely to have a second overdose, compared with those who no longer had an opioid prescription. The risk of a repeat overdose was greatest for patients taking the highest opioid doses.

In an editorial accompanying the study, Dr. Jessica Gregg of Central City Concern in Portland, Oregon, said many providers do not know when a patient overdoses. “There are no widespread systems in place, either within health plans or through governmental organizations, for notifying providers when overdoses occur,” she told Reuters.

“Patients who have misused their prescriptions are unlikely to report that misuse (and their subsequent overdose) to their prescriber out of concern that the provider will terminate their prescriptions,” Gregg said.