Folks taking opioids for chronic pain may run into trouble if they need to find a new doctor.

A new "secret shopper" survey of 194 Michigan primary care clinics found that as many as 4 out of 10 primary care doctors would turn away patients who have been taking the pain-killing medications (such as Percocet) long term. And that's true even if those physician practices said they are open to taking new patients.

"This is a prevalent problem—more so than we expected," said study author Dr. Pooja Lagisetty, from the University of Michigan Medical School and the VA Ann Arbor Healthcare System.

For the study, researchers called physician practices, posing as a potential new patient. The "patients" explained that they were taking opioids for chronic pain and said they had either Medicaid or private health insurance.

Dr. Lagisetty said she hopes the study gets healthcare systems thinking about this problem. "I hope it gets physicians thinking, 'What can we do better?' By closing doors on patients, we're not helping anybody," she said. "We need to dig into this problem to find out what's driving it."

Dr. Lagisetty said there are probably multiple reasons that doctors turn certain patients away. "Stigma is probably a component, and another big component is probably the administrative burden that comes with prescribing opioids. It's not a trivial amount of work to manage someone on opioids safely. I suspect some clinics may be a little overburdened," she said.

Dr. Noel Deep, a spokesman for the American College of Physicians, suspects the problem is less about stigma and more about the regulatory burden related to prescribing opioids. "Physicians have to think twice when prescribing opioids, and if you're in a small, rural practice, it gets difficult. Physicians can also be targeted for overprescribing," he said.

Dr. Yili Huang, director of the pain management center at Northwell Phelps Hospital in Sleepy Hollow, NY, agreed that opioid regulations might make physicians hesitant to take on a patient who's using them, even if that patient doesn't have an issue with addiction. While people taking opioids are at a very high risk of misuse or abuse, Dr. Huang said about three-quarters of people who take them don't misuse them and about 90% don't develop an addiction. He did note, however, that many people can have their pain successfully managed without opioids. But for those who do need them, the increased scrutiny and potential risk to a doctor's license and livelihood may keep them from taking on these patients.

So, what can happen if people treating chronic pain with opioids can't find a doctor? Dr. Lagisetty said patients could be left with uncontrolled pain, and may have withdrawal symptoms. If they attempt to see several doctors for opioids, they may be labeled as a "drug-seeker" and have difficulty accessing their pain medications.

For those who are abusing the opioids, in some states they won't have access to the medication that can reverse an overdose. They also won't get a referral for addiction treatment.

Dr. Deep said, "Patients have to come first. If patients can't get medications, there can be very bad outcomes." He noted that patients might end up driving long distances to seek pain relief. Some might even use illicit drugs.

All three experts said there's a need for increased addiction education, as well as some flexibility in prescribing guidelines.

The news from the study wasn't all bad, Dr. Lagisetty pointed out. While around 40% of doctors turned chronic opioid users away, 60% were willing to see them. Dr. Huang added, "Despite increasing regulatory scrutiny, many providers continue to care for patients on chronic opioids."

The study found no difference in whether doctors would see patients based on the type of insurance they had. "This suggests that there may not be any financial or discriminatory incentive behind these actions, and instead [turning these patients away] is driven solely by fear of policy repercussions and lack of education," Dr. Huang explained.

The study was recently published online in JAMA Network Open.