Spatial Access to Sterile Syringes and the Odds of Injecting with an Unsterile Syringe among Injectors: A Longitudinal Multilevel Study

Abstract

Despite the 2010 repeal of the ban on spending federal monies to fund syringe exchange programs (SEPs) in the USA, these interventions-and specifically SEP site locations-remain controversial. To further inform discussions about the location of SEP sites, this longitudinal multilevel study investigates the relationship between spatial access to sterile syringes distributed by SEPs in New York City (NYC) United Hospital Fund (UHF) districts and injecting with an unsterile syringe among injectors over time (1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006). Annual measures of spatial access to syringes in each UHF district (N = 42) were created using data on SEP site locations and site-specific syringe distribution data. Individual-level data on unsterile injecting among injectors (N = 4,067) living in these districts, and on individual-level covariates, were drawn from the Risk Factors study, an ongoing cross-sectional study of NYC drug users. We used multilevel models to explore the relationship of district-level access to syringes to the odds of injecting with an unsterile syringe in 975% of injection events in the past 6 months, and to test whether this relationship varied by district-level arrest rates (per 1,000 residents) for drug and drug paraphernalia possession. The relationship between district-level access to syringes and the odds of injecting with an unsterile syringe depended on district-level arrest rates. In districts with low baseline arrest rates, better syringe access was associated with a decline in the odds of frequently injecting with an unsterile syringe (AOR, 0.95). In districts with no baseline syringe access, higher arrest rates were associated with increased odds of frequently injecting with an unsterile syringe (AOR, 1.02) When both interventions were present, arrest rates eroded the protective effects of spatial access to syringes. Spatial access to syringes in small geographic areas appears to reduce the odds of injecting with an unsterile syringe among local injectors, and arrest rates elevate these odds. Policies and practices that curtail syringe flow in geographic areas (e.g., restrictions on SEP locations or syringe distribution) or that make it difficult for injectors to use the sterile syringes they have acquired may damage local injectors' efforts to reduce HIV transmission and other injection-related harms.

Piloting a ‘spatial isolation’ index: The built environment and sexual and drug use risks to sex workers

“…This observation is supported by results (not shown) suggesting bivariate relationships between reduced police harassment without arrest and increased: percent commercial zoning (P=0.001); number of light posts (P=0.032); and percent building footprint (P=0.089) (i.e., markers of spatial isolation). Heavier police presence has been associated with increased risk for transmission of blood-borne or sexually transmitted infections to SWs and drug users through a number of spatial pathways; for example, heavier arrest rates have negatively affected the association between increased spatial access to sterile syringes and the use of safe drug use equipment (Cooper, et al, 2012a; Cooper, et al, 2012b); increased police presence and previous arrests/harassment by police have been associated with rushed negotiations with clients or rushed and unsafe drug use, injecting and doing sex work in unsafe spaces and having safer sex and drug use equipment confiscated (Kerr & Wood, 2005; Shannon, et al, 2008a; Small, Kerr, Charette, Schechter, & Spittal, 2006); and being able to access safer indoor drug use spaces has alleviated the pressures of policing and violence in public drug use spaces and facilitated use of safer drug use equipment (Fairbairn, Small, Shannon, Wood, & Kerr, 2008). Such research helps explain our association between increased spatial isolation as measured by our index and exchanging sex for drugs.…”

“…The term ‘built environment’, has broad uses and applications, and in our paper refers to features of human-made spaces, places or surroundings in which human activity takes place. For example, the relationship between spatial access to sterile syringes, policing of drug use (arrests) and the use of safe drug use equipment has been assessed (Cooper, et al, 2012a; Cooper, et al, 2012b). An index measuring the cumulative effects of physical disorder within neighbourhoods (e.g., structural damage to homes; streets with trash, abandoned cars, graffiti; physical problems and building code violations in high schools), the ‘Broken Window Index’, was examined for its influence on neighborhood gonorrhea rates in New Orleans (Cohen, et al, 2000).…”

Association between neighbourhood socioeconomic characteristics and high-risk injection behaviour amongst injection drug users living in inner and other city areas in Montréal, Canada

“…In a recent special issue of the journal, Cooper et al applied geographic information system (GIS) techniques, specifically buffer zones, to create geographic measures of syringe exchange program access and law enforcement activities at small geographic area levels (Cooper 2008). Likewise, the use of GIS to create circular buffers centred on residents' homes has been used elsewhere to study the associations between local contextual conditions and health outcome (Chaix et al, 2005a;Chaix et al, 2005b;Chaix et al, 2006).…”

“…For IDUs as well as the average resident, a 10-minute walking distance, corresponding to a 500-meter buffer, is generally recognised as a reasonable radius by which to represent access to local services. (Cooper et al, 2008;Rockwell et al, 1999;Rockwell et al, 2002).…”

Associations of place characteristics with HIV and HCV risk behaviors among racial/ethnic groups of people who inject drugs in the United States

“…21–27 A smaller number determined whether other environmental features, including place-based socioeconomic factors, influence injection-related risk behavior and condomless sex among PWID. 28–31 Even fewer determine whether specific place-based features are associated with HIV/HCV risk behavior among different racial/ethnic groups of PWID.…”