Decreased diversion by doctor-shopping for a reformulated extended release oxycodone product (OxyContin)

Background: Doctor-shopping (obtaining prescriptions from multiple prescribers/pharmacies) for opioid analgesics produces a supply for diversion and abuse, and represents a major public health issue. Methods: An open cohort study assessed changes in doctor-shopping in the U.S. for a brand extended release (ER) oxycodone product (OxyContin) and comparator opioids before (July, 2009 to June, 2010) versus after (January, 2011 to June, 2013) introduction of reformulated brand ER oxycodone with abuse-deterrent properties, using IMS LRx longitudinal data covering >150 million patients and 65% of retail U.S. prescriptions. Results: After its reformulation, the rate of doctor-shopping decreased 50% (for 2+ prescribers/3+ pharmacies) for brand ER oxycodone, but not for comparators. The largest decreases in rates occurred among young adults (73%), those paying with cash (61%) and those receiving the highest available dose (62%), with a 90% decrease when stratifying by all three characteristics. The magnitude of doctor-shopping reductions increased with increasing number of prescribers/pharmacies (e.g., 75% reduction for ≥2 prescribers/≥4 pharmacies). Conclusions: The rate of doctor-shopping for brand ER oxycodone decreased substantially after its reformulation, which did not occur for other prescription opioids. The largest reductions in doctor-shopping occurred with characteristics associated with higher abuse risk such as youth, cash payment and high dose, and with more specific thresholds of doctor-shopping. A higher prescriber and/or pharmacy threshold also increased the magnitude of the decrease, suggesting that it better captured the effect of the reformulation on actual doctor-shoppers.