Association for Public Policy Analysis & Management

The misuse of prescription opioids has become a serious epidemic in the US. Between 1999 and 2010, both opioid prescriptions and deaths from opioid poisoning approximately quadrupled.  In addition, it became clear that many opioids available on the street for non-medical use had been diverted from legitimate prescriptions from well-meaning medical professionals.

Until recently, when President Obama announced a set of joint public-private initiatives, most policy activity in response to the epidemic had taken place at the state level.  Nearly every state has implemented a Prescription Drug Monitoring Program, or PDMP, that collects data on prescriptions for controlled substances to facilitate detection of suspicious prescribing and utilization.  While few providers participated in early systems, states have recently begun to require providers to access the PDMP under certain circumstances.  PDMP administrative data shows that such requirements increase the number of providers with PDMP logins and the total number of patient history queries, often by several orders of magnitude.  Low provider utilization of PDMPs without a "must access’’ requirement may explain why many studies find that PDMPs have little or no effect on opioid use or opioid-related outcomes.

In this paper, we assess the impact of PDMPs with and without a "must access’’ provision on opioid utilization and poisonings.   We estimate difference-in-difference models using Medicare claims data from 2007 to 2012. Our individual-level data allow us to measure rare outcomes in the upper tail of the utilization distribution – the exact outcomes that PDMPs are meant to impede.  For example, we find that 1.6% of those taking opioids obtain them from five or more prescribers in a six-month period. We can also observe individuals’ opioid poisoning incidents; such incidents are strongly predicted by our measures of misuse from the prescription drug claims.

We first show that a PDMP without a "must access’’ provision is not associated with opioid misuse in Medicare.  In contrast, we find that implementing a "must access’’ PDMP reduces the percentage of individuals obtaining opioids from five or more prescribers in a six month interval by 12%, and the percentage obtaining opioids from five or pharmacies by more than one-third. 

An individual can evade a state PDMP by traveling to another state; we create a novel outcome that measures whether an individual disproportionately obtains opioids from out-of-state prescribers or pharmacies (relative to her out-of-state rate for non-opioid prescriptions). We find that a "must access’’ PDMP raises the rate at which that state’s residents obtain opioids from out-of-state pharmacies by roughly a third of a standard deviation.

Additional analysis suggests a causal interpretation of our findings.  States that went on to implement "must access’’ PDMPs were similar prior to implementation to states that did not. In addition, we find similar results in each state that implements the policy.