The negative spillover effect of electronic prescribing for controlled substances on the opioid epidemic

The opioid epidemic poses widespread societal challenges. In response, electronic prescribing for controlled substances (EPCS), which requires prescribers to use the e-prescribing system, has begun attracting attention to combat the opioid epidemic by helping prescribers detect doctor shoppers and prevent forged prescriptions. However, a concern is that limited access to opioids after EPCS mandates may cause drug users to cross borders and travel to other areas without EPCS. Grounded in the tension on the efficacy of EPCS, this study aims to assess the impact of EPCS on the opioid dispensing rate. Leveraging a U.S. county-level data set from 2010 to 2020 and employing a quasi-experiment setup with matching, we find that counties without an EPCS mandate but adjacent to a state with an EPCS mandate experience an increase in opioid dispensing rates. Specifically, a neighboring-state EPCS mandate is associated with a 7.56% increase in the opioid dispensing rate in an adjacent county on average. The findings reveal that the negative spillover effect spreads deeper in areas with lenient illicit drug controls, in urban regions, and in areas with high poverty levels. Moreover, we estimate the overall efficacy of EPCS mandates by combining both the positive direct effect and the negative spillover effect of EPCS. We discuss theoretical and policy insights for the effective operation of EPCS mandates.