Race, rurality and geographic accessibility to medication for opioid use disorder in the US

Disparities in geographic access to medication for opioid use disorder (OUD) are well documented. Further, historical implications of systemic racism and of the longstanding War on Drugs in the United States have driven both social and spatial inequities in access to treatment. This work builds on a previously published spatial access methodology that uses a gravity-based variant of the enhanced two-step floating catchment area model, to determine how OUD pharmacotherapy accessibility varies nationally at the census tract level. Medication for OUD (MOUD) accessibility scores are then analyzed by rurality and racial/ethnic segregation. The Getis-Ord Gi* statistic was used to identify clusters of high or low accessibility to MOUD, while the interaction index was used as a measure of segregation to assess the racial/ethnic population distribution. The results of the clustering statistic, and the associated significance values were then compared to rurality and interaction using the Chi-Square test to determine if hot or cold areas of access are independent of rurality and racial/ethnic spatial distributions. Lastly, the percentage of buprenorphine providers at capacity by census tract was calculated using the binary 'at-capacity' data attribute associated with each SAMHSA buprenorphine provider record. The results demonstrate distinct spatial variability of MOUD resources based on urbanicity and racial makeup that have significant implications for intervention or policy reform that seeks to encourage equal access to both treatment modalities. MOUD access varies by racial segregation and rurality Black segregated and integrated Black-White urban communities have greater accessibility to both MOUD types White urban communities have significantly lower levels of spatial access to MOUD Low urban MOUD induction and adherence rates of minority populations are likely not strongly driven by spatial access, rather structural, political, physical, and social components are more influential to intervention uptake. 97% of buprenorphine providers were at their patient capacity limit prior to the end of the federal DATA waiver process in June 2023.