Medicaid prevalence and opioid use disorder treatment access disparities

To examine how variation in the size of the local Medicaid population moderates Medicaid-to-private treatment access differentials for women with opioid use disorder (OUD).

County-level information on total Medicaid enrollment combined with randomized field experiment data from 10 diverse states that used a simulated patient (audit) methodology to examine buprenorphine providers' appointment granting behavior.

We used multiple regression modeling approaches to capture the moderating influence of Medicaid prevalence on differences in the likelihood of receiving an insurance-covered appointment between Medicaid and privately insured female patients.

Completed calls to buprenorphine treatment providers.

We find a 0.37 percentage point (p value <0.01) narrowing of the Medicaid-to-private access gap with each one percentage point increase in the local insured population on Medicaid. There is effectively no difference in the likelihood of being granted an insurance-covered appointment across the two payer groups in the top tercile of Medicaid penetration.

When Medicaid is a common source of insurance within the local population, buprenorphine providers are much less likely to discriminate between Medicaid and privately insured prospective patients. Efforts to enhance equitable access across patient groups are perhaps best targeted where Medicaid prevalence is lower.