Spillover effects from health information systems integration: Evidence from prescription drug monitoring programs

To ease prescribers' burden in using statewide Prescription Drug Monitoring Programs (PDMPs), many US states have moved to better integrate PDMP data with patients' electronic health records (EHRs). While such PDMP-EHR integration is likely to reduce local formal prescription opioid consumption, in this paper, we explore the possibility that it induces individuals to seek opioids across state borders and/or at the local black market. We find that for a focal county, its neighboring state's PDMP-EHR integration leads to an increase in the focal county's consumption of prescription opioids, an undesirable cross-border spillover effect. Moreover, we find that this spillover effect is mitigated when prescribers in the focal county have access to the neighboring state's PDMP data via interstate PDMP data sharing. We also find nuanced evidence that a state's PDMP-EHR integration might induce an increase in its black-market prices of prescription opioids. While vertical information integration in a region (i.e., a state's PDMP-EHR integration) may fulfill its intended benefit, our findings suggest it may also result in a spillover effect on neighboring areas. Notably, a complementary horizontal information integration (in this case, interstate PDMP data sharing) could mitigate such an undesirable spillover effect. We discuss implications for the design of care delivery processes, particularly prescription processes, that rely on the studied health information systems.