Relationship of opioid prescription sales and overdoses, North Carolina

Background: In the United States, fatal drug overdoses have tripled since 1991. This escalation in deaths is believed to be driven primarily by prescription opioid medications. This investigation compared trends and patterns in sales of opioids, opioid drug overdoses treated in emergency departments (EDs), and unintentional overdose deaths in North Carolina (NC).

Methods: Our ecological study compared rates of opioid sales, opioid related ED overdoses, and unintentional drug overdose deaths in NC. Annual sales data, provided by the Drug Enforcement Administration, for select opioids were converted into morphine equivalents and aggregated by zip code. These opioid drug sales rates were trended from 1997 to 2010. In addition, opioid sales were correlated and compared to opioid related ED visits, which came from a Centers for Disease Control and Prevention syndromic surveillance system, and unintentional overdose deaths, which came from NC Vital Statistics, from 2008 to 2010. Finally, spatial cluster analysis was performed and rates were mapped by zip code in 2010.

Results: Opioid sales increased substantially from 1997 to 2010. From 2008 to 2010, the quarterly rates of opioid drug overdoses treated in EDs and opioid sales correlated (r=0.68, p=0.02). Specific regions of the state, particularly in the southern and western corners, had both high rates of prescription opioid sales and overdoses.

Conclusions: Temporal trends in sales of prescription opioids correlate with trends in opioid related ED visits. The spatial correlation of opioid sales with ED visit rates shows that opioid sales data may be a timely way to identify high-risk communities in the absence of timely ED data.