title: Estimating the prevalence of opioid diversion by "doctor shoppers" in the United States.
abstract: BACKGROUND
  Abuse of prescription opioid analgesics is a serious threat to public health, resulting in rising numbers of overdose deaths and admissions to emergency departments and treatment facilities. Absent adequate patient information systems, "doctor shopping" patients can obtain multiple opioid prescriptions for nonmedical use from different unknowing physicians. Our study estimates the prevalence of doctor shopping in the US and the amounts and types of opioids involved.
  
  
  RESULTS
  The sample included records for 146.1 million opioid prescriptions dispensed during 2008 by 76% of US retail pharmacies. Prescriptions were linked to unique patients and weighted to estimate all prescriptions and patients in the nation. Finite mixture models were used to estimate different latent patient populations having different patterns of using prescribers. On average, patients in the extreme outlying population (0.7% of purchasers), presumed to be doctor shoppers, obtained 32 opioid prescriptions from 10 different prescribers. They bought 1.9% of all opioid prescriptions, constituting 4% of weighed amounts dispensed.
  
  
  CONCLUSIONS
  Our data did not provide information to make a clinical diagnosis of individuals. Very few of these patients can be classified with certainty as diverting drugs for nonmedical purposes. However, even patients with legitimate medical need for opioids who use large numbers of prescribers may signal dangerously uncoordinated care. To close the information gap that makes doctor shopping and uncoordinated care possible, states have created prescription drug monitoring programs to collect records of scheduled drugs dispensed, but the majority of physicians do not access this information. To facilitate use by busy practitioners, most monitoring programs should improve access and response time, scan prescription data to flag suspicious purchasing patterns and alert physicians and pharmacists. Physicians could also prevent doctor shopping by adopting procedures to screen new patients for their risk of abuse and to monitor patients' adherence to prescribed treatments.
authors.affiliation: US Health Division, Abt Associates Inc., Cambridge, Massachusetts, USA. doug_mcdonald@abtassoc.com
authors.forename: Douglas C
authors.initials: DC
authors.lastname: McDonald
authors.forename: Kenneth E
authors.initials: KE
authors.lastname: Carlson
mesh_terms: D006801:Humans; D009293:Opioid-Related Disorders / Q000453:epidemiology*; D010818:Practice Patterns, Physicians'; D015995:Prevalence; D014481:United States / Q000453:epidemiology