Conversion to Persistent or High-Risk Opioid Use After a New Prescription From the Emergency Department: Evidence From Washington Medicaid Beneficiaries

Study objective: We describe the overall risk and factors associated with transitioning to persistent opioid or high-risk use after an initial emergency department (ED) opioid prescription. Methods: A retrospective cohort study of Washington Medicaid beneficiaries was performed with linked Medicaid and prescription drug monitoring program files. We identified adults who had no record of opioid prescriptions in the previous 12 months, and who filled a new opioid prescription within 1 day of an ED discharge in 2014. We assessed the risk of persistent opioid use or high-risk prescription fills within 12 months after the index visit. Logistic regression was used to assess the association between pertinent variables and conversion to persistent or high-risk use. Results: Among 202,807 index ED visits, 23,381 resulted in a new opioid prescription. Of these, 13.7% led to persistent or high-risk opioid prescription fills within 12 months compared with 3.2% for patients who received no opioids at the index visit. Factors associated with increased likelihood of persistent opioid or high-risk prescription fills included a history of skeletal or connective-tissue disorder; neck, back, or dental pain; and a history of prescribed benzodiazepines. The highest conversion rates (37.3%) were observed among visits in which greater than or equal to 350 morphine milligram equivalents were prescribed. Conversion rates remained greater than 10% even among visits resulting in lower-dose opioid prescriptions. Conclusion: Medicaid recipients are at moderate risk for conversion to persistent or high-risk opioid use after a new ED prescription. Longer or higher-dose prescriptions are associated with increased risk for conversion; however, even visits that lead to guideline-concordant prescriptions bear some risk for long-term or high-risk use.