Associations Between Copays, Coverage Limits for Opioid Use Disorder Medications, and Prescribing in Medicaid, 2018.

Background: Opioid use disorder (OUD) affects millions of Americans, but only a fraction receive treatment. Many patients with OUD are enrolled in Medicaid, but elements of different state Medicaid programs' drug benefit designs may impact patients' access to life-saving care.

Objective: To describe medication for OUD (mOUD) use in Medicaid and examine the relationship between mOUD use and state drug benefit design plans.

Design/subjects: Cross-sectional study using Medicaid State Drug Utilization Data from 2018 to quantify office-based mOUD and the Medicaid Behavioral Health Services Database to extract copay amounts and coverage limits for mOUD. We excluded states with <5% coverage and assessed for associations between copays or coverage limits and mOUD dispensing using simple linear regression.

Measures: Proportion of mOUD prescriptions relative to all prescriptions, opioid prescriptions, and the state-level prevalence of pain reliever use disorder and association between copays, coverage limits and these proportions.

Results: There was substantial variability in mOUD use. Although state Medicaid drug benefit designs also varied, we found no significant relationship between copay requirements (yes/no), coverage limits (yes/no), copay amount ($0-$0.99 vs. $1 or more), and mOUD utilization measures.

Conclusions: Substantial state-level variation exists in mOUD use, but we did not find a significant association between copays or coverage limits and use in Medicaid. Further research is needed to assess other potential impacts of mOUD drug benefit design elements in Medicaid.