Accessibility of methadone treatment via public transit for syringe services program participants in Miami-Dade County, Florida.

Methadone is an opioid receptor agonist medication used in the treatment of opioid use disorder (OUD). Geographic distance to opioid treatment programs (OTPs) is a major barrier to treatment, given requirements for direct observation of dosing and periodic drug screens, and 'methadone treatment deserts' are defined as a public transit threshold of 30 min. The purpose of this study was to examine public transit access to methadone treatment for participants of a syringe services program (SSP) in Miami-Dade County, Florida. Public transit times were calculated using the R library r5r, which facilitates multi-modal transportation network routing. General Transit Feed Specification data was combined with street network data from OpenStreetMap for Miami-Dade County. Transit times were estimated from the population-weighted centroid of each zip code (n = 73) with participants of Miami's only SSP (n = 1549) to the nearest OTP (n = 4) using 24 departure windows aligned with OTP service hours. The mean one-way transit time from zip codes with SSP participants in Miami-Dade County to the nearest OTP was 79 min. Over 95 % of SSP participants in Miami-Dade County have a mean one-way transit time >30 min, classifying them as residing in 'methadone treatment deserts.' Likewise, 69 of the 73 (95 %) zip codes with SSP participants have a mean transit time to the closest OTP >30 min. Transit times differ substantially between zip codes with different numbers of SSP participants, but not between departure windows. Geographic isolation of methadone treatment from public transit routes represents a significant barrier to equitable OUD treatment.