A multi-method spatial examination of factors associated with changes in geographic accessibility to buprenorphine providers in HEALing communities study states Kentucky, Massachusetts, and Ohio

Objectives

Access to substance use treatment is critical to reduce the risk of opioid overdose. However, analyzing geographic accessibility using singular measures may provide imprecise estimates. Our objective was to examine changes in geographic accessibility to buprenorphine providers across three HEALing Communities Study (HCS) states, Kentucky, Massachusetts, and Ohio in the US, using multiple spatial analyses and determining whether disparities in access existed across geographic regions and sociodemographic indicators.

Methods

We used buprenorphine provider data from the Drug Enforcement Administration database in January 2020 (reference point) and June 2022. We used four methods to examine changes in geographic accessibility to buprenorphine: 1) kernel density analysis; 2) change in rates analysis (at the county or municipality level); 3) minkowski distance (drive-time to the nearest provider); 4) enhanced 2-step floating catchment area (E2SFCA) and spatial regression analyses, controlling for HCS communities (Wave 1 or Wave 2) and other sociodemographic factors.

Results

We identified an increase in geographic accessibility to buprenorphine across all three states. Improvements in accessibility were concentrated in areas that had higher reference point access. While our regression model of change in the E2SFCA accessibility index shows that Wave 1 communities in Kentucky had a higher increase in access compared to the state average increase, we were not able to establish consistent associations between HCS communities and changes in the E2SFCA index.

Conclusion

Since geographic accessibility to buprenorphine treatment is critical, additional efforts are needed to improve access to buprenorphine providers in rural areas and areas with limited baseline access.