Physicians are a leading source of prescription opioids for those at the highest risk for abuse, according new research from the Centers for Disease Control and Prevention. The findings, published last Monday by JAMA Internal Medicine, undermine a popular belief that people who abuse narcotic pain relievers — including hydrocodone, oxycodone, and methadone — obtain them without a prescription.

By teasing out data on habitual nonmedical users from occasional ones, CDC researchers found that drug sources varied significantly depending on frequency of use.

Previous studies have shown that most nonmedical users of opioids obtained them from friends or family members for free. While the new study does not contradict those findings, it provides a more nuanced view of the group it considers to be at the highest risk for abuse. Researchers identified patterns among those most frequently abusing prescription drugs — 200 or more days a year — by analyzing responses from the years 2008 to 2011 in the National Survey on Drug Use and Health, the annual government-sponsored survey on illicit drug use, which includes diverted prescription drugs.

Among those reporting the most frequent nonmedical use of opioid analgesics, 27 percent of respondents said they obtained the drugs through their own prescriptions from one or more physician, a slightly greater source of the drugs than from friends or relatives. Frequent users were also more likely than others to buy prescriptions from people they know (23 percent) or from a drug dealer or stranger (15 percent.) In contrast, among lower-frequency users (1 to 29 days a year), friends and family remain the primary source of prescription pain relievers — they account for 62 percent of the diverted drugs.

“It’s a message to prescribers that not all diversion of drugs is happening by one person giving to another — like getting it for free from friends and family — that there are some people who are getting it directly from prescribers,” said Dr. Leonard J. Paulozzi, a co-author of the study and a prescription overdose specialist at the CDC.

One reason for that trend, Paulozzi said, may be that for heavy users, a prescription can better sustain a daily habit than acquaintances can, who may run out or become unwilling to give away more than just a few pills.

“We know that group of people has been increasing in numbers over the last decade, and is a group that is of higher risk for serious consequences of nonmedical use, such as prescription drug overdoses,” Paulozzi said.

Prescription pain relievers contributed to more than 16,000 overdose deaths in 2010 — a number that exceeds heroin and cocaine deaths combined, and has the CDC classifying prescription drug abuse as an epidemic.

Dr. Peter Abaci, medical director of the Bay Area Pain and Wellness Center, was not surprised to hear about the key role physicians have played in the prescription drug abuse crisis.

“Our society put a lot of pressure on doctors for a number of years to prescribe more opioids to patients,” Abaci said. “It became something like, if you didn’t do it, you weren’t a compassionate physician.”

However, Abaci pointed out that a lot has changed since 2011 — the most recent data used in the CDC study. For one thing, he said, the crackdown on rogue pain clinics and “pill mills” in Florida and other places have impacted many physicians’ prescribing habits.

“There’s a ripple effect for things like that; doctors become more conservative when these kind of things happen,” he said. “I think the pendulum has swung the other way again.”

Over the years, Dr. Abaci has also gravitated away from opioid analgesics for pain management in his own practice; instead, he aims to alleviate pain with a more holistic approach. Still, prescription pain relievers remain an important tool in some cases, he said, such as those undergoing cancer treatment, people with acute injuries, and end-of-life care.

When prescribing opioids, Dr. Abaci says some of the best practices include: screening for other drug use; discouraging early refills; and referencing the state prescription drug monitoring database to see if someone is getting medications from multiple sources, or “doctor shopping.”

Additionally, and perhaps most importantly, Abaci says getting to know your patients is crucial in efforts to prevent abuse.

“You want to be able to trust your patient,” Abaci said. “So I think a doctor needs to get to know the person, and that takes a little time. But if you can do that, that does help manage the situation a lot better.”