GIS Mapping of Access to OUD Treatment in Philadelphia ALONG Racially Segregated Lines

Philadelphia witnessed increasing rates of opioid use disorder (OUD) over the last decade. The number of fatal overdoses from opioid use in the City rose from 211 in 2003 to 1,074 in 2017, and most recently to 1,044 in 2020 (Philadelphia Department of Public Health, 2020). Redlining, a practice used by the New Deal era Home Owners’ Loan Corporation (HOLC), to determine which neighborhoods in cities with populations greater than 40,000 were worthy of investment by banks, may have had long-term consequences on economic and racial segregation that persists in urban America today (Faber, 2020). However, whether this impact involved a divestment in treatment programs for OUD has yet to be examined.

Study Design:

This research involved retrieving public information from the Substance Abuse and Mental Health Services Administration’s (SAMHSA) buprenorphine Treatment Practitioner Locator. The point data was merged, using Alteryx, with data from the SAMHSA directory of certified methadone Opioid Treatment Programs (OTPs) in Philadelphia. The postal addresses of the buprenorphine and methadone OUD treatment providers were then geocoded in ArcGIS using the ESRI World Locator and plotted against digitized maps from the HOLC archives (Nelson, et al., 2022). The effect of redlining on buprenorphine service presence was estimated by a chi-square goodness-of-fit test. Given the relatively small sample of OTPs, we applied Fisher’s Exact Test to examine the impact of “positive” versus “negative” grades on the presence or absence of methadone sites.

Population Studied:

This study explored how racialized redlining from 1937 affected OUD treatment accessibility in Philadelphia in 2022 using GIS mapping techniques and basic inferential statistics. Specifically, the hypothesis was that “negative” HOLC grades resulted in the absence of methadone treatment facilities in historically White enclaves, and that there would be no effect of redlining on the distribution of buprenorphine providers across these districts.

Principal Findings:

Visual inspection of the map of services alone indicated that there are no OTPs present in historically White communities, per the HOLC grading system. A count of clinics revealed no OTPs in neighborhoods graded “Best” investments, and only one OTP in the neighborhoods graded “Still Desirable”. The remaining 18 methadone clinics are located in geographies that received grades of “Definitely in Decline” or “Hazardous” in 1937. On the other hand, while a cluster of buprenorphine providers appeared in the Center City region of Philadelphia, the remainder tended to be relatively well-distributed across traditionally White neighborhoods. Statistical analyses supported these conclusions.

Conclusions:

Redlining in 1937 resulted in programs placed in economically disadvantaged neighborhoods, which may impede access to services. These policies, rooted in a legacy of systematic racism and exclusion against Black, Brown, and immigrant communities in the U.S.

Implications for Policy or Practice:

Policymakers and advocates alike must be aware of the racialized nature of NIMBY-style grassroots activism that emerged in response to the establishment of new services for consumers of OUD treatments. Whether the treatment involves buprenorphine or methadone, no one should be denied access to treatment for OUD based on their place of residence. Indeed, when NIMBY-style politics trump documented public health needs, the result is that everyone loses.