A geospatial analysis of access to syringe services programs in the United States, 2023

Syringe services programs (SSPs) deliver essential services to people who use drugs, including safer drug use supplies, infectious disease testing, and naloxone distribution. Geographic proximity influences SSP utilization and health outcomes, yet no national measures of travel-time access exist. We estimated geographic access to SSPs across the United States and assessed alignment with factors related to need.

We conducted a cross-sectional analysis of 701 SSPs operating in 2023 and listed in the Syringe Services Programs in the U.S.

SSP addresses were geocoded; 30-minute driving and 20-minute walking isochrones were generated and spatially intersected with Census division, state, county-level centers of population, adult population, rurality, and lagged drug overdose mortality rates RESULTS: Overall, 63% of U.S. adults lived within a 30-minute drive of an SSP, but only 2.5% within a 20-minute walk. Drive-time access varied by rurality (urban: 93%, suburban: 62%, rural: 18%) and overdose mortality level (high: 70%, moderate: 61%, low: 62%). Walk-time access was extremely limited across all strata, ranging from 0.7% in rural counties to 9.6% in urban counties. Only seven states achieved > 67% drive-time coverage across all mortality levels. Access was generally higher in counties with greater need, though 30% and 92% of adults in high-mortality counties remained beyond 30-minute drive or 20-minute walk, respectively.

Substantial geographic barriers limit SSP access, particularly for walking and in rural areas. Expanding SSP implementation and alternative delivery models (mobile units, mail-based distribution, vending machines) are needed to ensure equitable access to harm reduction services.