Spatial and Nonspatial Factors Associated with Access to Medication for Opioid Use Disorder among Pregnant Women in Massachusetts.

Introduction: In Massachusetts, one-third of pregnant women with opioid use disorder (OUD) do not receive medications for OUD (MOUD), such as buprenorphine and methadone. Research has demonstrated that broadly, access to medications differs by location and by socioeconomic and geographic characteristics of communities, but a comprehensive understanding at the micro-level is lacking. This study aims to identify and characterize access to MOUD treatment among pregnant women in Massachusetts.

Methods: We used enhanced two-step floating catchment area analyses, which incorporated supply and demand measures, as well as local drive-time, to determine spatial accessibility to MOUD. We used four publicly available data sources to calculate geographic accessibility to MOUD. We then merged the resulting accessibility indices with data from the American Community Survey to statistically analyze ZIP Code Tabulation Area (ZCTA) characteristics that were associated with geographic accessibility to MOUD among the study population.

Results: We calculated access to 258 opioid (methadone and/or buprenorphine) treatment programs and 2,585 buprenorphine-waivered prescribers among 74,969 pregnant women during the period 2016-2020 in 448 ZCTAs (= 537 ZCTAs). ZCTAs with lower accessibility to both types of MOUD were concentrated in Western Massachusetts. Central Massachusetts had poor accessibility to buprenorphine providers. Accessibility was greater in ZCTAs that were nonmetropolitan, that had higher minority status and langauge vulnerability, and that had less extreme concentration of privilege.

Conclusions: There is a need to improve MOUD access overall, and to enhance access to both types of medications, so pregnant women can choose the one that works best for them.