Less than one percent of patients – about 135,000 people — who purchase prescription painkillers in the U.S. were classified as "doctor shoppers" in the first national study of opioid prescriptions and sales records.
But while they make up only a small proportion of the 48 million patients who are prescribed painkillers, researchers say patients who visit multiple doctors and pharmacies to obtain opioids are having an outsized impact on the system. Federal and state officials have cracked down on the illicit use of painkillers by making it harder for patients to obtain opioids – even ones with legitimate prescriptions.
The study found that the vast majority of patients prescribed opioids did not abuse the drugs or visit a suspicious number of doctors.
"We estimate that a small outlying population of approximately one of every 143 patients who purchased opioids from retail pharmacies in 2008 obtained these prescriptions from a suspiciously large number of different prescribers. Patients in this population got an average of 32 prescriptions from an average of 10 different physicians," wrote researchers Douglas McDonald and Kenneth Carlson of Abt Associates.
The study, published online in the journal PLOS ONE, analyzed records for over 146 million prescriptions dispensed in 2008 for opioids containing buprenorphine, codeine, fentanyl, hydrocodone, methadone, oxycodone, oxymorphone, propoxyphene, or tramadol.
The drugs were prescribed by over 900,000 doctors, dispensed by about 37,000 pharmacies, and given to over 48 million patients.
Patients classified as doctor shoppers purchased 4.3 million prescriptions, or nearly 2 percent of all opioid prescriptions sold in 2008. Some doctor shoppers saw over 200 different physicians that year, often crossing state lines to obtain prescriptions.
"The amounts of opioids purchased by patients in this extreme population are another strong signal of doctor shopping – an estimated average of 109 morphine equivalent milligrams per patient per day for the entire year. Even if these patients did not divert drugs for illicit purposes, obtaining opioids from such large numbers of prescribers may signal dangerously uncoordinated care," the researchers said.
To prevent abuse, most states have created prescription drug monitoring programs (PMPs) to collect sales records of painkillers. But studies have found that many physicians do not access PMPs before writing patients' prescriptions. Many PMPs are not "user friendly" and often have rules that frustrate doctors. Physician awareness about the tools is poor, and some states restrict access, opening the database only to law enforcement officials.
"Ultimately, the front lines of defense against drug diversion by deceptive patients are manned by physicians and other healthcare providers who are authorized to prescribe scheduled drugs. Many of these providers are ill prepared," the researchers said.
"Pain management has not been traditionally been a part of the curriculum in medical schools and surveys of physicians have found their knowledge of pain management principles to be deficient."
The researchers said physicians could prevent doctor shopping by screening new patients for their risk of abuse and by monitoring their adherence to prescribed treatments. They also recommend that PMPs and health insurers scan prescription data to flag suspicious activity that may indicate doctor shopping, and then alert physicians and pharmacists about the patients.
The study found that most patients who were prescribed opioids did not abuse the drugs or used them sparingly.
Among patients using opioids during the first 2 months of 2008, 43% did not use the drugs for the rest of the year. Of those patients who continued to use opioids, 31% received their prescriptions from 1 physician and 14% from 2 physicians. About 3% of patients obtained prescriptions from 5 to 9 prescribers.
