Spatial Access to Syringe Exchange Programs and Pharmacies Selling Over-the-Counter Syringes as Predictors of Drug Injectors' Use of Sterile Syringes

摘要

Objectives. We examined relationships of spatial access to syringe exchange programs (SEPs) and pharmacies selling over-the-counter (OTC) syringes with New York City drug injectors’ harm reduction practices. Methods. Each year from 1995 to 2006, we measured the percentage of 42 city health districts’ surface area that was within 1 mile of an SEP or OTC pharmacy. We applied hierarchical generalized linear models to investigate relationships between these exposures and the odds that injectors (n = 4003) used a sterile syringe for at least 75% of injections in the past 6 months. Results . A 1-unit increase in the natural log of the percentage of a district's surface area within a mile of an SEP in 1995 was associated with a 26% increase in the odds of injecting with a sterile syringe; a 1-unit increase in this exposure over time increased these odds 23%. A 1-unit increase in the natural log of OTC pharmacy access improved these odds 15%. Conclusions . Greater spatial access to SEPs and OTC pharmacies improved injectors’ capacity to engage in harm reduction practices that reduce HIV and HCV transmission. Research indicates that individuals who live closer to mental health and primary care clinics are more likely to use these services. 1 – 5 Accordingly, the US Department of Health and Human Services and other public health agencies promote easy spatial access to health care service sites in small geographic areas (e.g., clusters of census tracts). 6 , 7 Syringe exchange programs (SEPs) and pharmacies that sell syringes without a prescription, or over the counter (OTC), are health care services that substantially increase the likelihood that drug injectors will use sterile syringes, thus reducing their probability of becoming infected with HIV, HCV, and possibly other injection-related bacterial infections. 8 – 19 Multiple studies have concluded that the prevalence of injection-related HIV and related risk behaviors is higher in nations, states, and other large geographic areas with poor spatial access to SEPs or OTC pharmacies, 9 , 20 – 25 but little research has focused on the impact of spatial access to SEPs and OTC pharmacies in small geographic areas on local injectors’ injection practices and rates of injection-related infection. Spatial access to SEPs and OTC pharmacies often varies across small geographic areas within a city, metropolitan area, or state. Municipal ordinances may prohibit SEPs from operating within a specific distance of a school or park, and local opposition may prevent a new SEP from opening in a neighborhood or may force an existing SEP to close. 26 – 28 Some states permit pharmacies to choose whether to sell OTC syringes, and the distribution of pharmacies themselves across neighborhoods is uneven. 29 – 31 The few studies of local access to SEPs have found that, as with other health services, 1 – 5 proximity increases utilization. 32 – 35 For example, Rockwell et al. found that injectors living within a 10-minute travel distance of an SEP in New York City in 1993 were almost 3 times as likely as other injectors to attend an SEP and half as likely to report injecting with used syringes. 33 A recent study, however, found no relationship between OTC pharmacy access and injection-related behaviors among injectors living within 1 kilometer of a pharmacy. 34 Quantifying the effect of spatial access to SEPs on injection practices in local areas is particularly pressing now. After decades of withholding federal funds from SEPs, the US Congress in 2009 approved an appropriations bill permitting federal funding of SEPs. These funds could permit new SEPs to open and allow existing SEPs to add sites. As the appropriations bill underwent congressional review, the geographic location of federally funded SEPs became a source of debate. The House version of the bill restricted federal funding to SEPs located more than 1000 feet from an educational institution, public recreation area, “or an event sponsored by any such entity.” 36 (sec523) The Senate version contained no geographic restrictions. The final appropriations bill shifts decisions about SEP locations to local governments: the bill prohibits granting federal funds to SEPs located in sites “that local public health or law enforcement agencies determine to be inappropriate.” 37 (p8) Research on the effect of spatial access to SEPs on injection practices may inform local advocacy and decisions about which SEP sites may receive federal funding. We conducted a longitudinal (1995–2006) multilevel analysis of whether variations in spatial access to SEPs and OTC pharmacies across New York City health districts affected the likelihood that local injectors used sterile syringes. Although state law required a prescription to purchase a syringe throughout the study period, syringe access has evolved over time. St